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PIC18FXX2 Data Sheet
High Performance, Enhanced FLASH Microcontrollers with 10-Bit A/D
2002 Microchip Technology Inc.
DS39564B
Note the following details of the code protection feature on PICmicro(R) MCUs. * * * The PICmicro family meets the specifications contained in the Microchip Data Sheet. Microchip believes that its family of PICmicro microcontrollers is one of the most secure products of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the PICmicro microcontroller in a manner outside the operating specifications contained in the data sheet. The person doing so may be engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable". Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our product.
* * *
If you have any further questions about this matter, please contact the local sales office nearest to you.
Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. No representation or warranty is given and no liability is assumed by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip's products as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights.
Trademarks The Microchip name and logo, the Microchip logo, KEELOQ, MPLAB, PIC, PICmicro, PICSTART and PRO MATE are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, microID, MXDEV, MXLAB, PICMASTER, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. dsPIC, dsPICDEM.net, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, microPort, Migratable Memory, MPASM, MPLIB, MPLINK, MPSIM, PICC, PICDEM, PICDEM.net, rfPIC, Select Mode and Total Endurance are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. Serialized Quick Turn Programming (SQTP) is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. (c) 2002, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.
Printed on recycled paper.
Microchip received QS-9000 quality system certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona in July 1999 and Mountain View, California in March 2002. The Company's quality system processes and procedures are QS-9000 compliant for its PICmicro(R) 8-bit MCUs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, non-volatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001 certified.
DS39564B - page ii
2002 Microchip Technology Inc.
M
Device FLASH (bytes) PIC18F242 PIC18F252 PIC18F442 PIC18F452 16K 32K 16K 32K
PIC18FXX2
Peripheral Features (Continued):
* Addressable USART module: - Supports RS-485 and RS-232 * Parallel Slave Port (PSP) module
28/40-pin High Performance, Enhanced FLASH Microcontrollers with 10-Bit A/D
High Performance RISC CPU:
* C compiler optimized architecture/instruction set - Source code compatible with the PIC16 and PIC17 instruction sets * Linear program memory addressing to 32 Kbytes * Linear data memory addressing to 1.5 Kbytes
On-Chip Program Memory On-Chip Data RAM EEPROM # Single Word (bytes) (bytes) Instructions 8192 16384 8192 16384 768 1536 768 1536 256 256 256 256
Analog Features:
* Compatible 10-bit Analog-to-Digital Converter module (A/D) with: - Fast sampling rate - Conversion available during SLEEP - Linearity 1 LSb * Programmable Low Voltage Detection (PLVD) - Supports interrupt on-Low Voltage Detection * Programmable Brown-out Reset (BOR)
* Up to 10 MIPs operation: - DC - 40 MHz osc./clock input - 4 MHz - 10 MHz osc./clock input with PLL active * 16-bit wide instructions, 8-bit wide data path * Priority levels for interrupts * 8 x 8 Single Cycle Hardware Multiplier
Special Microcontroller Features:
* 100,000 erase/write cycle Enhanced FLASH program memory typical * 1,000,000 erase/write cycle Data EEPROM memory * FLASH/Data EEPROM Retention: > 40 years * Self-reprogrammable under software control * Power-on Reset (POR), Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) * Watchdog Timer (WDT) with its own On-Chip RC Oscillator for reliable operation * Programmable code protection * Power saving SLEEP mode * Selectable oscillator options including: - 4X Phase Lock Loop (of primary oscillator) - Secondary Oscillator (32 kHz) clock input * Single supply 5V In-Circuit Serial ProgrammingTM (ICSPTM) via two pins * In-Circuit Debug (ICD) via two pins
Peripheral Features:
* High current sink/source 25 mA/25 mA * Three external interrupt pins * Timer0 module: 8-bit/16-bit timer/counter with 8-bit programmable prescaler * Timer1 module: 16-bit timer/counter * Timer2 module: 8-bit timer/counter with 8-bit period register (time-base for PWM) * Timer3 module: 16-bit timer/counter * Secondary oscillator clock option - Timer1/Timer3 * Two Capture/Compare/PWM (CCP) modules. CCP pins that can be configured as: - Capture input: capture is 16-bit, max. resolution 6.25 ns (TCY/16) - Compare is 16-bit, max. resolution 100 ns (TCY) - PWM output: PWM resolution is 1- to 10-bit, max. PWM freq. @: 8-bit resolution = 156 kHz 10-bit resolution = 39 kHz * Master Synchronous Serial Port (MSSP) module, Two modes of operation: - 3-wire SPITM (supports all 4 SPI modes) - I2CTM Master and Slave mode
CMOS Technology:
* Low power, high speed FLASH/EEPROM technology * Fully static design * Wide operating voltage range (2.0V to 5.5V) * Industrial and Extended temperature ranges * Low power consumption: - < 1.6 mA typical @ 5V, 4 MHz - 25 A typical @ 3V, 32 kHz - < 0.2 A typical standby current
2002 Microchip Technology Inc.
DS39564B-page 1
PIC18FXX2
Pin Diagrams
RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1 RA0/AN0 MCLR/VPP NC RB7/PGD RB6/PGC RB5/PGM RB4 NC 6 5 4 3 2 1 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29
PLCC
RA4/T0CKI RA5/AN4/SS/LVDIN RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VDD VSS OSC1/CLKI OSC2/CLKO/RA6 RC0/T1OSO/T1CKI NC
7 8 9 10 11 12 13 14 15 16 171
PIC18F442 PIC18F452
RB3/CCP2* RB2/INT2 RB1/INT1 RB0/INT0 VDD VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT
TQFP
44 43 42 41 40 39 38 37 36 35 34 RC7/RX/DT RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7 VSS VDD RB0/INT0 RB1/INT1 RB2/INT2 RB3/CCP2* 1 2 3 4 5 6 7 8 9 10 11 33 32 31 30 29 28 27 26 25 24 23 NC RC0/T1OSO/T1CKI OSC2/CLKO/RA6 OSC1/CLKI VSS VDD RE2/AN7/CS RE1/AN6/WR RE0/AN5/RD RA5/AN4/SS/LVDIN RA4/T0CKI
* RB3 is the alternate pin for the CCP2 pin multiplexing.
RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 RD1/PSP1 RD0/PSP0 RC3/SCK/SCL RC2/CCP1 RC1/T1OSI/CCP2* NC
28 27 26 25 24 23 22 21 20 19 8 NC RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2 RD1/PSP1 RD0/PSP0 RC3/SCK/SCL RC2/CCP1 RC1/T1OSI/CCP2*
PIC18F442 PIC18F452
22 21 20 19 18 17 16 15 14 13 12
RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1 RA0/AN0 MCLR/VPP RB7/PGD RB6/PGC RB5/PGM RB4 NC NC
DS39564B-page 2
2002 Microchip Technology Inc.
PIC18FXX2
Pin Diagrams (Cont.'d)
DIP
MCLR/VPP RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4/SS/LVDIN RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VDD VSS OSC1/CLKI OSC2/CLKO/RA6 RC0/T1OSO/T1CKI RC1/T1OSI/CCP2* RC2/CCP1 RC3/SCK/SCL RD0/PSP0 RD1/PSP1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 RB7/PGD RB6/PGC RB5/PGM RB4 RB3/CCP2* RB2/INT2 RB1/INT1 RB0/INT0 VDD VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA RD3/PSP3 RD2/PSP2
PIC18F442
Note: Pin compatible with 40-pin PIC16C7X devices.
DIP, SOIC
MCLR/VPP RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4/SS/LVDIN VSS OSC1/CLKI OSC2/CLKO/RA6 RC0/T1OSO/T1CKI RC1/T1OSI/CCP2* RC2/CCP1 RC3/SCK/SCL 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 RB7/PGD RB6/PGC RB5/PGM RB4 RB3/CCP2* RB2/INT2 RB1/INT1 RB0/INT0 VDD VSS RC7/RX/DT RC6/TX/CK RC5/SDO RC4/SDI/SDA
PIC18F242
* RB3 is the alternate pin for the CCP2 pin multiplexing.
2002 Microchip Technology Inc.
PIC18F252
PIC18F452
DS39564B-page 3
PIC18FXX2
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7 2.0 Oscillator Configurations ............................................................................................................................................................ 17 3.0 Reset .......................................................................................................................................................................................... 25 4.0 Memory Organization ................................................................................................................................................................. 35 5.0 FLASH Program Memory ........................................................................................................................................................... 55 6.0 Data EEPROM Memory ............................................................................................................................................................. 65 7.0 8 X 8 Hardware Multiplier ........................................................................................................................................................... 71 8.0 Interrupts .................................................................................................................................................................................... 73 9.0 I/O Ports ..................................................................................................................................................................................... 87 10.0 Timer0 Module ......................................................................................................................................................................... 103 11.0 Timer1 Module ......................................................................................................................................................................... 107 12.0 Timer2 Module ......................................................................................................................................................................... 111 13.0 Timer3 Module ......................................................................................................................................................................... 113 14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 117 15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 125 16.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART).............................................................. 165 17.0 Compatible 10-bit Analog-to-Digital Converter (A/D) Module................................................................................................... 181 18.0 Low Voltage Detect .................................................................................................................................................................. 189 19.0 Special Features of the CPU .................................................................................................................................................... 195 20.0 Instruction Set Summary .......................................................................................................................................................... 211 21.0 Development Support............................................................................................................................................................... 253 22.0 Electrical Characteristics .......................................................................................................................................................... 259 23.0 DC and AC Characteristics Graphs and Tables ....................................................................................................................... 289 24.0 Packaging Information.............................................................................................................................................................. 305 Appendix A: Revision History ............................................................................................................................................................ 313 Appendix B: Device Differences........................................................................................................................................................ 313 Appendix C: Conversion Considerations........................................................................................................................................... 314 Appendix D: Migration from Baseline to Enhanced Devices ............................................................................................................. 314 Appendix E: Migration from Mid-range to Enhanced Devices........................................................................................................... 315 Appendix F: Migration from High-end to Enhanced Devices ............................................................................................................ 315 Index .................................................................................................................................................................................................. 317 On-Line Support................................................................................................................................................................................. 327 Reader Response .............................................................................................................................................................................. 328 PIC18FXX2 Product Identification System......................................................................................................................................... 329
DS39564B-page 4
2002 Microchip Technology Inc.
PIC18FXX2
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@mail.microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback.
Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: * Microchip's Worldwide Web site; http://www.microchip.com * Your local Microchip sales office (see last page) * The Microchip Corporate Literature Center; U.S. FAX: (480) 792-7277 When contacting a sales office or the literature center, please specify which device, revision of silicon and data sheet (include literature number) you are using.
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Register on our web site at www.microchip.com/cn to receive the most current information on all of our products.
2002 Microchip Technology Inc.
DS39564B-page 5
PIC18FXX2
NOTES:
DS39564B-page 6
2002 Microchip Technology Inc.
PIC18FXX2
1.0 DEVICE OVERVIEW
This document contains device specific information for the following devices: * PIC18F242 * PIC18F252 * PIC18F442 * PIC18F452 The following two figures are device block diagrams sorted by pin count: 28-pin for Figure 1-1 and 40/44-pin for Figure 1-2. The 28-pin and 40/44-pin pinouts are listed in Table 1-2 and Table 1-3, respectively.
These devices come in 28-pin and 40/44-pin packages. The 28-pin devices do not have a Parallel Slave Port (PSP) implemented and the number of Analog-toDigital (A/D) converter input channels is reduced to 5. An overview of features is shown in Table 1-1.
TABLE 1-1:
DEVICE FEATURES
PIC18F242 DC - 40 MHz 16K 8192 768 256 17 Ports A, B, C 4 2 MSSP, Addressable USART -- 5 input channels POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST) Yes Yes 75 Instructions 28-pin DIP 28-pin SOIC PIC18F252 DC - 40 MHz 32K 16384 1536 256 17 Ports A, B, C 4 2 MSSP, Addressable USART -- 5 input channels POR, BOR, RESET Instruction, Stack Full, Stack Underflow (PWRT, OST) Yes Yes 75 Instructions 28-pin DIP 28-pin SOIC PIC18F442 DC - 40 MHz 16K 8192 768 256 18 4 2 MSSP, Addressable USART PSP 8 input channels PIC18F452 DC - 40 MHz 32K 16384 1536 256 18 4 2 MSSP, Addressable USART PSP 8 input channels
Features Operating Frequency Program Memory (Bytes) Program Memory (Instructions) Data Memory (Bytes) Data EEPROM Memory (Bytes) Interrupt Sources I/O Ports Timers Capture/Compare/PWM Modules Serial Communications Parallel Communications 10-bit Analog-to-Digital Module
Ports A, B, C, D, E Ports A, B, C, D, E
RESETS (and Delays)
POR, BOR, POR, BOR, RESET Instruction, RESET Instruction, Stack Full, Stack Full, Stack Underflow Stack Underflow (PWRT, OST) (PWRT, OST) Yes Yes 75 Instructions 40-pin DIP 44-pin PLCC 44-pin TQFP Yes Yes 75 Instructions 40-pin DIP 44-pin PLCC 44-pin TQFP
Programmable Low Voltage Detect Programmable Brown-out Reset Instruction Set Packages
2002 Microchip Technology Inc.
DS39564B-page 7
PIC18FXX2
FIGURE 1-1: PIC18F2X2 BLOCK DIAGRAM
Data Bus<8>
21 21
Table Pointer
Data Latch
PORTA RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4/SS/LVDIN RA6
8
inc/dec logic
8
8
Data RAM
Address Latch Address Latch Program Memory (up to 2 Mbytes) Data Latch 31 Level Stack
21
PCLATU PCLATH
12
(2)
PCU PCH PCL Program Counter
Address<12>
4
BSR
12
FSR0 FSR1 FSR2 inc/dec logic
4
Bank0, F
12
16
Table Latch
Decode
8
ROM Latch
PORTB
Instruction Register Instruction Decode & Control
8
PRODH PRODL
RB0/INT0 RB1/INT1 RB2/INT2 RB3/CCP2(1) RB4 RB5/PGM RB6/PCG RB7/PGD
OSC2/CLKO OSC1/CLKI Timing Generation
3 Power-up Timer Oscillator Start-up Timer Power-on Reset 4X PLL Watchdog Timer Brown-out Reset Low Voltage Programming In-Circuit Debugger
8 x 8 Multiply
8
BIT OP WREG
T1OSCI T1OSCO
8 8
8
8
ALU<8>
PORTC RC0/T1OSO/T1CKI RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT
Precision Voltage Reference MCLR VDD, VSS
8
Timer0
Timer1
Timer2
Timer3
A/D Converter
CCP1
CCP2
Master Synchronous Serial Port
Addressable USART
Data EEPROM
Note
1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit. 2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction). 3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations are device dependent.
DS39564B-page 8
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 1-2: PIC18F4X2 BLOCK DIAGRAM
Data Bus<8> PORTA 21 21
Table Pointer
Data Latch 8 8 8 Data RAM (up to 4K address reach) Address Latch
(2)
inc/dec logic
Address Latch Program Memory (up to 2 Mbytes) Data Latch
21
PCLATU PCLATH
RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4/SS/LVDIN RA6
PCU PCH PCL Program Counter
12 Address<12> PORTB 4
BSR
12 FSR0 FSR1 FSR2
inc/dec logic
4
Bank0, F
31 Level Stack
12
16
Table Latch
Decode 8
ROM Latch
RB0/INT0 RB1/INT1 RB2/INT2 RB3/CCP2(1) RB4 RB5/PGM RB6/PCG RB7/PGD
PORTC RC0/T1OSO/T1CKI RC1/T1OSI/CCP2(1) RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT
Instruction Register
Instruction Decode & Control OSC2/CLKO OSC1/CLKI Timing Generation 3 Power-up Timer Oscillator Start-up Timer Power-on Reset 4X PLL Watchdog Timer Brown-out Reset Low Voltage Programming In-Circuit Debugger
8 PRODH PRODL 8 x 8 Multiply 8 BIT OP 8 WREG 8 8 ALU<8> 8 PORTE 8 PORTD
T1OSCI T1OSCO
RD0/PSP0 RD1/PSP1 RD2/PSP2 RD3/PSP3 RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7
Precision Voltage Reference MCLR VDD, VSS
RE0/AN5/RD RE1/AN6/WR RE2/AN7/CS
Timer0
Timer1
Timer2
Timer3
A/D Converter
CCP1
CCP2
Master Synchronous Serial Port
Addressable USART
Parallel Slave Port
Data EEPROM
Note
1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit. 2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction). 3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations are device dependent.
2002 Microchip Technology Inc.
DS39564B-page 9
PIC18FXX2
TABLE 1-2:
Pin Name DIP MCLR/VPP MCLR VPP NC OSC1/CLKI OSC1 CLKI -- 9 -- 9 I I ST CMOS 1
PIC18F2X2 PINOUT I/O DESCRIPTIONS
Pin Number Pin SOIC Type 1 I I -- ST ST -- Buffer Type Description Master Clear (input) or high voltage ICSP programming enable pin. Master Clear (Reset) input. This pin is an active low RESET to the device. High voltage ICSP programming enable pin. These pins should be left unconnected. Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate. General Purpose I/O pin. PORTA is a bi-directional I/O port.
OSC2/CLKO/RA6 OSC2 CLKO
10
10 O O -- --
RA6 RA0/AN0 RA0 AN0 RA1/AN1 RA1 AN1 RA2/AN2/VREFRA2 AN2 VREFRA3/AN3/VREF+ RA3 AN3 VREF+ RA4/T0CKI RA4 T0CKI RA5/AN4/SS/LVDIN RA5 AN4 SS LVDIN RA6 2 2
I/O
TTL
I/O I 3 3 I/O I 4 4 I/O I I 5 5 I/O I I 6 6 I/O I 7 7 I/O I I I
TTL Analog TTL Analog TTL Analog Analog TTL Analog Analog ST/OD ST TTL Analog ST Analog
Digital I/O. Analog input 0. Digital I/O. Analog input 1. Digital I/O. Analog input 2. A/D Reference Voltage (Low) input. Digital I/O. Analog input 3. A/D Reference Voltage (High) input. Digital I/O. Open drain when configured as output. Timer0 external clock input. Digital I/O. Analog input 4. SPI Slave Select input. Low Voltage Detect Input. See the OSC2/CLKO/RA6 pin. CMOS = CMOS compatible input or output I = Input P = Power
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
DS39564B-page 10
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 1-2:
Pin Name DIP
PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number Pin Type SOIC Buffer Type Description PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs.
RB0/INT0 RB0 INT0 RB1/INT1 RB1 INT1 RB2/INT2 RB2 INT2 RB3/CCP2 RB3 CCP2 RB4 RB5/PGM RB5 PGM RB6/PGC RB6 PGC RB7/PGD RB7 PGD
21
21 I/O I TTL ST TTL ST TTL ST TTL ST TTL Digital I/O. External Interrupt 0.
22
22 I/O I External Interrupt 1. Digital I/O. External Interrupt 2. Digital I/O. Capture2 input, Compare2 output, PWM2 output. Digital I/O. Interrupt-on-change pin. Digital I/O. Interrupt-on-change pin. Low Voltage ICSP programming enable pin. Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming clock pin. Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. CMOS = CMOS compatible input or output I = Input P = Power
23
23 I/O I
24
24 I/O I/O
25 26
25 26
I/O
I/O I/O 27 27 I/O I/O 28 28 I/O I/O
TTL ST TTL ST TTL ST
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
2002 Microchip Technology Inc.
DS39564B-page 11
PIC18FXX2
TABLE 1-2:
Pin Name DIP RC0/T1OSO/T1CKI RC0 T1OSO T1CKI RC1/T1OSI/CCP2 RC1 T1OSI CCP2 RC2/CCP1 RC2 CCP1 RC3/SCK/SCL RC3 SCK SCL RC4/SDI/SDA RC4 SDI SDA RC5/SDO RC5 SDO RC6/TX/CK RC6 TX CK RC7/RX/DT RC7 RX DT VSS VDD 11
PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number Pin Type SOIC 11 I/O O I 12 12 I/O I I/O 13 13 I/O I/O 14 14 I/O I/O I/O 15 15 I/O I I/O 16 16 I/O O 17 17 I/O O I/O 18 18 I/O I I/O 8, 19 20 8, 19 20 P P ST ST ST -- -- Digital I/O. USART Asynchronous Receive. USART Synchronous Data (see related TX/CK). Ground reference for logic and I/O pins. Positive supply for logic and I/O pins. CMOS = CMOS compatible input or output I = Input P = Power ST -- ST Digital I/O. USART Asynchronous Transmit. USART Synchronous Clock (see related RX/DT). ST -- Digital I/O. SPI Data Out. ST ST ST Digital I/O. SPI Data In. I2C Data I/O. ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2C mode ST ST Digital I/O. Capture1 input/Compare1 output/PWM1 output. ST CMOS ST Digital I/O. Timer1 oscillator input. Capture2 input, Compare2 output, PWM2 output. ST -- ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. Buffer Type Description PORTC is a bi-directional I/O port.
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
DS39564B-page 12
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 1-3:
Pin Name DIP MCLR/VPP MCLR VPP NC OSC1/CLKI OSC1 -- 13 14 30 I ST 1
PIC18F4X2 PINOUT I/O DESCRIPTIONS
Pin Number Pin Type PLCC TQFP 2 18 I I -- ST ST -- Buffer Type Description Master Clear (input) or high voltage ICSP programming enable pin. Master Clear (Reset) input. This pin is an active low RESET to the device. High voltage ICSP programming enable pin. These pins should be left unconnected. Oscillator crystal or external clock input. Oscillator crystal input or external clock source input. ST buffer when configured in RC mode, CMOS otherwise. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General Purpose I/O pin. PORTA is a bi-directional I/O port.
CLKI
I
CMOS
OSC2/CLKO/RA6 OSC2 CLKO
14
15
31 O O -- --
RA6 RA0/AN0 RA0 AN0 RA1/AN1 RA1 AN1 RA2/AN2/VREFRA2 AN2 VREFRA3/AN3/VREF+ RA3 AN3 VREF+ RA4/T0CKI RA4 T0CKI RA5/AN4/SS/LVDIN RA5 AN4 SS LVDIN RA6 2 3 19
I/O
TTL
I/O I 3 4 20 I/O I 4 5 21 I/O I I 5 6 22 I/O I I 6 7 23 I/O I 7 8 24 I/O I I I
TTL Analog TTL Analog TTL Analog Analog TTL Analog Analog ST/OD ST TTL Analog ST Analog
Digital I/O. Analog input 0. Digital I/O. Analog input 1. Digital I/O. Analog input 2. A/D Reference Voltage (Low) input. Digital I/O. Analog input 3. A/D Reference Voltage (High) input. Digital I/O. Open drain when configured as output. Timer0 external clock input. Digital I/O. Analog input 4. SPI Slave Select input. Low Voltage Detect Input. (See the OSC2/CLKO/RA6 pin.) CMOS = CMOS compatible input or output I = Input P = Power
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
2002 Microchip Technology Inc.
DS39564B-page 13
PIC18FXX2
TABLE 1-3:
Pin Name DIP
PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number Pin Type PLCC TQFP Buffer Type Description PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs.
RB0/INT0 RB0 INT0 RB1/INT1 RB1 INT1 RB2/INT2 RB2 INT2 RB3/CCP2 RB3 CCP2 RB4 RB5/PGM RB5 PGM RB6/PGC RB6 PGC RB7/PGD RB7 PGD
33
36
8 I/O I TTL ST TTL ST TTL ST TTL ST TTL TTL ST TTL ST Digital I/O. External Interrupt 0.
34
37
9 I/O I External Interrupt 1. Digital I/O. External Interrupt 2. Digital I/O. Capture2 input, Compare2 output, PWM2 output. Digital I/O. Interrupt-on-change pin. Digital I/O. Interrupt-on-change pin. Low Voltage ICSP programming enable pin. Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming clock pin. Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. CMOS = CMOS compatible input or output I = Input P = Power
35
38
10 I/O I
36
39
11 I/O I/O
37 38
41 42
14 15
I/O I/O I/O
39
43
16 I/O I/O
40
44
17 I/O I/O TTL ST
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
DS39564B-page 14
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 1-3:
Pin Name DIP RC0/T1OSO/T1CKI RC0 T1OSO T1CKI RC1/T1OSI/CCP2 RC1 T1OSI CCP2 RC2/CCP1 RC2 CCP1 RC3/SCK/SCL RC3 SCK SCL RC4/SDI/SDA RC4 SDI SDA RC5/SDO RC5 SDO RC6/TX/CK RC6 TX CK RC7/RX/DT RC7 RX DT 23 25 42 I/O I I/O 24 26 43 I/O O 25 27 44 I/O O I/O 26 29 1 I/O I I/O ST ST ST Digital I/O. USART Asynchronous Receive. USART Synchronous Data (see related TX/CK). CMOS = CMOS compatible input or output I = Input P = Power ST -- ST Digital I/O. USART Asynchronous Transmit. USART Synchronous Clock (see related RX/DT). ST -- Digital I/O. SPI Data Out. ST ST ST Digital I/O. SPI Data In. I2C Data I/O. 15
PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number Pin Type PLCC TQFP 16 32 I/O O I 16 18 35 I/O I I/O 17 19 36 I/O I/O 18 20 37 I/O I/O I/O ST ST ST Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2C mode. ST ST Digital I/O. Capture1 input/Compare1 output/PWM1 output. ST CMOS ST Digital I/O. Timer1 oscillator input. Capture2 input, Compare2 output, PWM2 output. ST -- ST Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. Buffer Type Description PORTC is a bi-directional I/O port.
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
2002 Microchip Technology Inc.
DS39564B-page 15
PIC18FXX2
TABLE 1-3:
Pin Name DIP
PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number Pin Type PLCC TQFP Buffer Type Description PORTD is a bi-directional I/O port, or a Parallel Slave Port (PSP) for interfacing to a microprocessor port. These pins have TTL input buffers when PSP module is enabled.
RD0/PSP0 RD1/PSP1 RD2/PSP2 RD3/PSP3 RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7
19 20 21 22 27 28 29 30
21 22 23 24 30 31 32 33
38 39 40 41 2 3 4 5
I/O I/O I/O I/O I/O I/O I/O I/O
ST TTL ST TTL ST TTL ST TTL ST TTL ST TTL ST TTL ST TTL
Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. Digital I/O. Parallel Slave Port Data. PORTE is a bi-directional I/O port.
RE0/RD/AN5 RE0 RD AN5 RE1/WR/AN6 RE1 WR AN6 RE2/CS/AN7 RE2 CS AN7 VSS VDD
8
9
25
I/O ST TTL Analog Digital I/O. Read control for parallel slave port (see also WR and CS pins). Analog input 5. Digital I/O. Write control for parallel slave port (see CS and RD pins). Analog input 6. Digital I/O. Chip Select control for parallel slave port (see related RD and WR). Analog input 7. Ground reference for logic and I/O pins. Positive supply for logic and I/O pins. CMOS = CMOS compatible input or output I = Input P = Power
9
10
26
I/O ST TTL Analog
10
11
27
I/O ST TTL Analog
12, 31 13, 34 6, 29 11, 32 12, 35 7, 28
P P
-- --
Legend: TTL = TTL compatible input ST = Schmitt Trigger input with CMOS levels O = Output OD = Open Drain (no P diode to VDD)
DS39564B-page 16
2002 Microchip Technology Inc.
PIC18FXX2
2.0
2.1
OSCILLATOR CONFIGURATIONS
Oscillator Types
TABLE 2-1:
CAPACITOR SELECTION FOR CERAMIC RESONATORS
Ranges Tested:
The PIC18FXX2 can be operated in eight different Oscillator modes. The user can program three configuration bits (FOSC2, FOSC1, and FOSC0) to select one of these eight modes: 1. 2. 3. 4. 5. 6. 7. 8. LP XT HS HS + PLL RC RCIO EC ECIO Low Power Crystal Crystal/Resonator High Speed Crystal/Resonator High Speed Crystal/Resonator with PLL enabled External Resistor/Capacitor External Resistor/Capacitor with I/O pin enabled External Clock External Clock with I/O pin enabled
Mode XT
Freq
C1
C2
455 kHz 68 - 100 pF 68 - 100 pF 2.0 MHz 15 - 68 pF 15 - 68 pF 4.0 MHz 15 - 68 pF 15 - 68 pF HS 8.0 MHz 10 - 68 pF 10 - 68 pF 16.0 MHz 10 - 22 pF 10 - 22 pF These values are for design guidance only. See notes following this table. Resonators Used: 455 kHz Panasonic EFO-A455K04B 0.3% 2.0 MHz Murata Erie CSA2.00MG 0.5% 4.0 MHz Murata Erie CSA4.00MG 0.5% 8.0 MHz Murata Erie CSA8.00MT 0.5% 16.0 MHz Murata Erie CSA16.00MX 0.5% All resonators used did not have built-in capacitors.
2.2
Crystal Oscillator/Ceramic Resonators
In XT, LP, HS or HS+PLL Oscillator modes, a crystal or ceramic resonator is connected to the OSC1 and OSC2 pins to establish oscillation. Figure 2-1 shows the pin connections. The PIC18FXX2 oscillator design requires the use of a parallel cut crystal. Note: Use of a series cut crystal may give a frequency out of the crystal manufacturers specifications.
Note 1: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 2: When operating below 3V VDD, or when using certain ceramic resonators at any voltage, it may be necessary to use high-gain HS mode, try a lower frequency resonator, or switch to a crystal oscillator. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components, or verify oscillator performance.
FIGURE 2-1:
CRYSTAL/CERAMIC RESONATOR OPERATION (HS, XT OR LP CONFIGURATION)
OSC1 To Internal Logic SLEEP
C1(1)
XTAL
RS(2) C2(1) OSC2
RF(3)
PIC18FXXX
Note 1: See Table 2-1 and Table 2-2 recommended values of C1 and C2.
for
2: A series resistor (RS) may be required for AT strip cut crystals. 3: RF varies with the Oscillator mode chosen.
2002 Microchip Technology Inc.
DS39564B-page 17
PIC18FXX2
TABLE 2-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR
Ranges Tested: Mode LP XT Freq 32.0 kHz 200 kHz 200 kHz 1.0 MHz 4.0 MHz HS 4.0 MHz 8.0 MHz 20.0 MHz 25.0 MHz C1 33 pF 15 pF 22-68 pF 15 pF 15 pF 15 pF 15-33 pF 15-33 pF 15-33 pF C2 33 pF 15 pF 22-68 pF 15 pF 15 pF 15 pF 15-33 pF 15-33 pF 15-33 pF
2.3
RC Oscillator
For timing-insensitive applications, the "RC" and "RCIO" device options offer additional cost savings. The RC oscillator frequency is a function of the supply voltage, the resistor (REXT) and capacitor (CEXT) values and the operating temperature. In addition to this, the oscillator frequency will vary from unit to unit due to normal process parameter variation. Furthermore, the difference in lead frame capacitance between package types will also affect the oscillation frequency, especially for low CEXT values. The user also needs to take into account variation due to tolerance of external R and C components used. Figure 2-3 shows how the R/C combination is connected. In the RC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Note: If the oscillator frequency divided by 4 signal is not required in the application, it is recommended to use RCIO mode to save current.
These values are for design guidance only. See notes following this table. Crystals Used 32.0 kHz 200 kHz 1.0 MHz 4.0 MHz 8.0 MHz 20.0 MHz Epson C-001R32.768K-A STD XTL 200.000KHz ECS ECS-10-13-1 ECS ECS-40-20-1 Epson CA-301 8.000M-C Epson CA-301 20.000M-C 20 PPM 20 PPM 50 PPM 50 PPM 30 PPM 30 PPM
FIGURE 2-3:
VDD REXT
RC OSCILLATOR MODE
Note 1: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 2: Rs may be required in HS mode, as well as XT mode, to avoid overdriving crystals with low drive level specification. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components., or verify oscillator performance. An external clock source may also be connected to the OSC1 pin in the HS, XT and LP modes, as shown in Figure 2-2.
OSC1 CEXT VSS FOSC/4 OSC2/CLKO
Internal Clock
PIC18FXXX
Recommended values:3 k REXT 100 k CEXT > 20pF
The RCIO Oscillator mode functions like the RC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6).
FIGURE 2-2:
EXTERNAL CLOCK INPUT OPERATION (HS, XT OR LP OSC CONFIGURATION)
OSC1
Clock from Ext. System Open
PIC18FXXX
OSC2
DS39564B-page 18
2002 Microchip Technology Inc.
PIC18FXX2
2.4 External Clock Input
FIGURE 2-5:
The EC and ECIO Oscillator modes require an external clock source to be connected to the OSC1 pin. The feedback device between OSC1 and OSC2 is turned off in these modes to save current. There is no oscillator start-up time required after a Power-on Reset or after a recovery from SLEEP mode. In the EC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 2-4 shows the pin connections for the EC Oscillator mode.
EXTERNAL CLOCK INPUT OPERATION (ECIO CONFIGURATION)
OSC1
Clock from Ext. System RA6
PIC18FXXX
I/O (OSC2)
2.5
HS/PLL
FIGURE 2-4:
EXTERNAL CLOCK INPUT OPERATION (EC CONFIGURATION)
OSC1
A Phase Locked Loop circuit is provided as a programmable option for users that want to multiply the frequency of the incoming crystal oscillator signal by 4. For an input clock frequency of 10 MHz, the internal clock frequency will be multiplied to 40 MHz. This is useful for customers who are concerned with EMI due to high frequency crystals. The PLL can only be enabled when the oscillator configuration bits are programmed for HS mode. If they are programmed for any other mode, the PLL is not enabled and the system clock will come directly from OSC1. The PLL is one of the modes of the FOSC<2:0> configuration bits. The Oscillator mode is specified during device programming. A PLL lock timer is used to ensure that the PLL has locked before device execution starts. The PLL lock timer has a time-out that is called TPLL.
Clock from Ext. System FOSC/4
PIC18FXXX
OSC2
The ECIO Oscillator mode functions like the EC mode, except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of PORTA (RA6). Figure 2-5 shows the pin connections for the ECIO Oscillator mode.
FIGURE 2-6:
PLL BLOCK DIAGRAM
(from Configuration HS Osc bit Register) PLL Enable Phase Comparator FIN Crystal Osc FOUT OSC1 Divide by 4
OSC2
Loop Filter
VCO MUX SYSCLK
2002 Microchip Technology Inc.
DS39564B-page 19
PIC18FXX2
2.6 Oscillator Switching Feature
The PIC18FXX2 devices include a feature that allows the system clock source to be switched from the main oscillator to an alternate low frequency clock source. For the PIC18FXX2 devices, this alternate clock source is the Timer1 oscillator. If a low frequency crystal (32 kHz, for example) has been attached to the Timer1 oscillator pins and the Timer1 oscillator has been enabled, the device can switch to a Low Power Execution mode. Figure 2-7 shows a block diagram of the system clock sources. The clock switching feature is enabled by programming the Oscillator Switching Enable (OSCSEN) bit in Configuration Register1H to a '0'. Clock switching is disabled in an erased device. See Section 11.0 for further details of the Timer1 oscillator. See Section 19.0 for Configuration Register details.
FIGURE 2-7:
DEVICE CLOCK SOURCES
PIC18FXXX
Main Oscillator OSC2 SLEEP OSC1 Timer1 Oscillator T1OSO T1OSCEN Enable Oscillator Clock Source option for other modules 4 x PLL TOSC TT1P TOSC/4 TSCLK
T1OSI
Clock Source
MUX
DS39564B-page 20
2002 Microchip Technology Inc.
PIC18FXX2
2.6.1 SYSTEM CLOCK SWITCH BIT
Note: The Timer1 oscillator must be enabled and operating to switch the system clock source. The Timer1 oscillator is enabled by setting the T1OSCEN bit in the Timer1 control register (T1CON). If the Timer1 oscillator is not enabled, then any write to the SCS bit will be ignored (SCS bit forced cleared) and the main oscillator will continue to be the system clock source. The system clock source switching is performed under software control. The system clock switch bit, SCS (OSCCON<0>) controls the clock switching. When the SCS bit is '0', the system clock source comes from the main oscillator that is selected by the FOSC configuration bits in Configuration Register1H. When the SCS bit is set, the system clock source will come from the Timer1 oscillator. The SCS bit is cleared on all forms of RESET.
REGISTER 2-1:
OSCCON REGISTER
U-0 -- bit 7 U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- R/W-1 SCS bit 0
bit 7-1 bit 0
Unimplemented: Read as '0' SCS: System Clock Switch bit When OSCSEN configuration bit = '0' and T1OSCEN bit is set: 1 = Switch to Timer1 oscillator/clock pin 0 = Use primary oscillator/clock input pin When OSCSEN and T1OSCEN are in other states: bit is forced clear Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
2002 Microchip Technology Inc.
DS39564B-page 21
PIC18FXX2
2.6.2 OSCILLATOR TRANSITIONS
The PIC18FXX2 devices contain circuitry to prevent "glitches" when switching between oscillator sources. Essentially, the circuitry waits for eight rising edges of the clock source that the processor is switching to. This ensures that the new clock source is stable and that its pulse width will not be less than the shortest pulse width of the two clock sources. A timing diagram indicating the transition from the main oscillator to the Timer1 oscillator is shown in Figure 2-8. The Timer1 oscillator is assumed to be running all the time. After the SCS bit is set, the processor is frozen at the next occurring Q1 cycle. After eight synchronization cycles are counted from the Timer1 oscillator, operation resumes. No additional delays are required after the synchronization cycles.
FIGURE 2-8:
TIMING DIAGRAM FOR TRANSITION FROM OSC1 TO TIMER1 OSCILLATOR
Q1 Q2
Q3 Q4
Q1 TT1P 1 2 3 4 Tscs 5 6 7 8
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
T1OSI OSC1 TOSC Internal System Clock SCS (OSCCON<0>) Program Counter PC TDLY
PC + 2
PC + 4
Note 1: Delay on internal system clock is eight oscillator cycles for synchronization.
The sequence of events that takes place when switching from the Timer1 oscillator to the main oscillator will depend on the mode of the main oscillator. In addition to eight clock cycles of the main oscillator, additional delays may take place.
If the main oscillator is configured for an external crystal (HS, XT, LP), then the transition will take place after an oscillator start-up time (TOST) has occurred. A timing diagram, indicating the transition from the Timer1 oscillator to the main oscillator for HS, XT and LP modes, is shown in Figure 2-9.
FIGURE 2-9:
Q3
TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS, XT, LP)
Q4 Q1 TT1P Q1 Q2 Q3 Q4 Q1 Q2 Q3
T1OSI OSC1 TOST OSC2 Internal System Clock SCS (OSCCON<0>) TOSC 1 2 3 4 5 TSCS 6 7 8
Program Counter
PC
PC + 2
PC + 6
Note 1: TOST = 1024 TOSC (drawing not to scale).
DS39564B-page 22
2002 Microchip Technology Inc.
PIC18FXX2
If the main oscillator is configured for HS-PLL mode, an oscillator start-up time (TOST) plus an additional PLL time-out (TPLL) will occur. The PLL time-out is typically 2 ms and allows the PLL to lock to the main oscillator frequency. A timing diagram indicating the transition from the Timer1 oscillator to the main oscillator for HS-PLL mode is shown in Figure 2-10.
FIGURE 2-10:
TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS WITH PLL)
Q4
Q1
TT1P
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
T1OSI OSC1 TOST OSC2 PLL Clock Input Internal System Clock SCS (OSCCON<0>) Program Counter PC PC + 2 PC + 4 TOSC
1 2 3
TPLL
TSCS
4 5 6 7 8
Note 1: TOST = 1024 TOSC (drawing not to scale).
If the main oscillator is configured in the RC, RCIO, EC or ECIO modes, there is no oscillator start-up time-out. Operation will resume after eight cycles of the main oscillator have been counted. A timing diagram, indicating the transition from the Timer1 oscillator to the main oscillator for RC, RCIO, EC and ECIO modes, is shown in Figure 2-11.
FIGURE 2-11:
Q3
TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (RC, EC)
Q4 Q1 TT1P Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
T1OSI OSC1 OSC2 Internal System Clock SCS (OSCCON<0>)
TOSC 1 2 3 4 5 6 7 8
TSCS Program Counter PC PC + 2 PC + 4
Note 1: RC Oscillator mode assumed.
2002 Microchip Technology Inc.
DS39564B-page 23
PIC18FXX2
2.7 Effects of SLEEP Mode on the On-Chip Oscillator
switching currents have been removed, SLEEP mode achieves the lowest current consumption of the device (only leakage currents). Enabling any on-chip feature that will operate during SLEEP will increase the current consumed during SLEEP. The user can wake from SLEEP through external RESET, Watchdog Timer Reset, or through an interrupt.
When the device executes a SLEEP instruction, the on-chip clocks and oscillator are turned off and the device is held at the beginning of an instruction cycle (Q1 state). With the oscillator off, the OSC1 and OSC2 signals will stop oscillating. Since all the transistor
TABLE 2-3:
OSC1 AND OSC2 PIN STATES IN SLEEP MODE
OSC1 Pin OSC2 Pin
OSC Mode RC
Note:
Floating, external resistor At logic low should pull high RCIO Floating, external resistor Configured as PORTA, bit 6 should pull high ECIO Floating Configured as PORTA, bit 6 EC Floating At logic low LP, XT, and HS Feedback inverter disabled, at Feedback inverter disabled, at quiescent voltage level quiescent voltage level See Table 3-1, in the "Reset" section, for time-outs due to SLEEP and MCLR Reset.
2.8
Power-up Delays
Power up delays are controlled by two timers, so that no external RESET circuitry is required for most applications. The delays ensure that the device is kept in RESET, until the device power supply and clock are stable. For additional information on RESET operation, see Section 3.0. The first timer is the Power-up Timer (PWRT), which optionally provides a fixed delay of 72 ms (nominal) on power-up only (POR and BOR). The second timer is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable.
With the PLL enabled (HS/PLL Oscillator mode), the time-out sequence following a Power-on Reset is different from other Oscillator modes. The time-out sequence is as follows: First, the PWRT time-out is invoked after a POR time delay has expired. Then, the Oscillator Start-up Timer (OST) is invoked. However, this is still not a sufficient amount of time to allow the PLL to lock at high frequencies. The PWRT timer is used to provide an additional fixed 2 ms (nominal) time-out to allow the PLL ample time to lock to the incoming clock frequency.
DS39564B-page 24
2002 Microchip Technology Inc.
PIC18FXX2
3.0 RESET
The PIC18FXXX differentiates between various kinds of RESET: a) b) c) d) e) f) g) h) Power-on Reset (POR) MCLR Reset during normal operation MCLR Reset during SLEEP Watchdog Timer (WDT) Reset (during normal operation) Programmable Brown-out Reset (BOR) RESET Instruction Stack Full Reset Stack Underflow Reset Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. Status bits from the RCON register, RI, TO, PD, POR and BOR, are set or cleared differently in different RESET situations, as indicated in Table 3-2. These bits are used in software to determine the nature of the RESET. See Table 3-3 for a full description of the RESET states of all registers. A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 3-1. The Enhanced MCU devices have a MCLR noise filter in the MCLR Reset path. The filter will detect and ignore small pulses. The MCLR pin is not driven low by any internal RESETS, including the WDT.
Most registers are unaffected by a RESET. Their status is unknown on POR and unchanged by all other RESETS. The other registers are forced to a "RESET state" on Power-on Reset, MCLR, WDT Reset, Brownout Reset, MCLR Reset during SLEEP and by the RESET instruction.
FIGURE 3-1:
RESET Instruction
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
Stack Pointer
Stack Full/Underflow Reset External Reset
MCLR WDT Module VDD Rise Detect VDD Brown-out Reset OST/PWRT OST 10-bit Ripple Counter OSC1 PWRT On-chip RC OSC(1) 10-bit Ripple Counter R Q Chip_Reset Power-on Reset S SLEEP WDT Time-out Reset
BOREN
Enable PWRT Enable OST(2) Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin. 2: See Table 3-1 for time-out situations.
2002 Microchip Technology Inc.
DS39564B-page 25
PIC18FXX2
3.1 Power-On Reset (POR) 3.3 Oscillator Start-up Timer (OST)
A Power-on Reset pulse is generated on-chip when VDD rise is detected. To take advantage of the POR circuitry, just tie the MCLR pin directly (or through a resistor) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. A minimum rise rate for VDD is specified (parameter D004). For a slow rise time, see Figure 3-2. When the device starts normal operation (i.e., exits the RESET condition), device operating parameters (voltage, frequency, temperature, etc.) must be met to ensure operation. If these conditions are not met, the device must be held in RESET until the operating conditions are met. The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over (parameter 32). This ensures that the crystal oscillator or resonator has started and stabilized. The OST time-out is invoked only for XT, LP and HS modes and only on Power-on Reset or wake-up from SLEEP.
3.4
PLL Lock Time-out
FIGURE 3-2:
EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP)
VDD
With the PLL enabled, the time-out sequence following a Power-on Reset is different from other Oscillator modes. A portion of the Power-up Timer is used to provide a fixed time-out that is sufficient for the PLL to lock to the main oscillator frequency. This PLL lock time-out (TPLL) is typically 2 ms and follows the oscillator start-up time-out (OST).
3.5
Brown-out Reset (BOR)
D
R R1 MCLR C
PIC18FXXX
Note 1: External Power-on Reset circuit is required only if the VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 k is recommended to make sure that the voltage drop across R does not violate the device's electrical specification. 3: R1 = 100 to 1 k will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS).
A configuration bit, BOREN, can disable (if clear/ programmed), or enable (if set) the Brown-out Reset circuitry. If VDD falls below parameter D005 for greater than parameter 35, the brown-out situation will reset the chip. A RESET may not occur if VDD falls below parameter D005 for less than parameter 35. The chip will remain in Brown-out Reset until VDD rises above BVDD. If the Power-up Timer is enabled, it will be invoked after VDD rises above BVDD; it then will keep the chip in RESET for an additional time delay (parameter 33). If VDD drops below BVDD while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above BVDD, the Power-up Timer will execute the additional time delay.
3.6
Time-out Sequence
3.2
Power-up Timer (PWRT)
The Power-up Timer provides a fixed nominal time-out (parameter 33) only on power-up from the POR. The Power-up Timer operates on an internal RC oscillator. The chip is kept in RESET as long as the PWRT is active. The PWRT's time delay allows VDD to rise to an acceptable level. A configuration bit is provided to enable/disable the PWRT. The power-up time delay will vary from chip-to-chip due to VDD, temperature and process variation. See DC parameter D033 for details.
On power-up, the time-out sequence is as follows: First, PWRT time-out is invoked after the POR time delay has expired. Then, OST is activated. The total time-out will vary based on oscillator configuration and the status of the PWRT. For example, in RC mode with the PWRT disabled, there will be no time-out at all. Figure 3-3, Figure 3-4, Figure 3-5, Figure 3-6 and Figure 3-7 depict time-out sequences on power-up. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, the time-outs will expire. Bringing MCLR high will begin execution immediately (Figure 3-5). This is useful for testing purposes or to synchronize more than one PIC18FXXX device operating in parallel. Table 3-2 shows the RESET conditions for some Special Function Registers, while Table 3-3 shows the RESET conditions for all the registers.
DS39564B-page 26
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 3-1: TIME-OUT IN VARIOUS SITUATIONS
Power-up(2) Brown-out PWRTE = 0 72 ms + 1024 TOSC + 2ms 72 ms + 1024 TOSC 72 ms 72 ms PWRTE = 1 1024 TOSC + 2 ms 1024 TOSC -- -- 72 ms(2) + 1024 TOSC + 2 ms 72 ms(2) + 1024 TOSC 72 ms
(2)
Oscillator Configuration HS with PLL enabled(1) HS, XT, LP EC External RC
Wake-up from SLEEP or Oscillator Switch 1024 TOSC + 2 ms 1024 TOSC -- --
72 ms(2)
Note 1: 2 ms is the nominal time required for the 4x PLL to lock. 2: 72 ms is the nominal power-up timer delay, if implemented.
REGISTER 3-1:
RCON REGISTER BITS AND POSITIONS
R/W-0 IPEN bit 7 Note 1: Refer to Section 4.14 (page 53) for bit definitions. U-0 -- U-0 -- R/W-1 RI R-1 TO R-1 PD R/W-0 POR R/W-0 BOR bit 0
TABLE 3-2:
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER
Program Counter 0000h 0000h 0000h 0000h 0000h 0000h 0000h PC + 2 0000h PC + 2(1) RCON Register 0--1 1100 0--u uuuu 0--0 uuuu 0--u uu11 0--u uu11 0--u 10uu 0--u 01uu u--u 00uu 0--1 11u0 u--u 00uu RI 1 u 0 u u u 1 u 1 u TO 1 u u u u 1 0 0 1 1 PD 1 u u u u 0 1 0 1 0 POR 0 u u u u u u u 1 u BOR 0 u u u u u u u 0 u STKFUL u u u u 1 u u u u u STKUNF u u u 1 u u u u u u
Condition Power-on Reset MCLR Reset during normal operation Software Reset during normal operation Stack Full Reset during normal operation Stack Underflow Reset during normal operation MCLR Reset during SLEEP WDT Reset WDT Wake-up Brown-out Reset Interrupt wake-up from SLEEP
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0' Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the interrupt vector (0x000008h or 0x000018h).
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PIC18FXX2
TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS
Power-on Reset, Brown-out Reset ---0 0000 0000 0000 0000 0000 00-0 0000 ---0 0000 0000 0000 0000 0000 --00 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx xxxx xxxx 0000 000x 1111 -1-1 11-0 0-00 N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx xxxx xxxx N/A N/A N/A N/A N/A MCLR Resets WDT Reset RESET Instruction Stack Resets ---0 0000 0000 0000 0000 0000 uu-0 0000 ---0 0000 0000 0000 0000 0000 --00 0000 0000 0000 0000 0000 0000 0000 uuuu uuuu uuuu uuuu 0000 000u 1111 -1-1 11-0 0-00 N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu uuuu uuuu N/A N/A N/A N/A N/A Wake-up via WDT or Interrupt ---0 uuuu(3) uuuu uuuu(3) uuuu uuuu(3) uu-u uuuu(3) ---u uuuu uuuu uuuu PC + 2(2) --uu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu(1) uuuu -u-u(1) uu-u u-uu(1) N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu uuuu uuuu N/A N/A N/A N/A N/A
Register
Applicable Devices
TOSU TOSH TOSL STKPTR PCLATU PCLATH PCL TBLPTRU TBLPTRH TBLPTRL TABLAT PRODH PRODL INTCON INTCON2 INTCON3 INDF0 POSTINC0 POSTDEC0 PREINC0 PLUSW0 FSR0H FSR0L WREG INDF1 POSTINC1 POSTDEC1 PREINC1 PLUSW1
242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242
442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442
252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252
452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read '0'. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read '0'.
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PIC18FXX2
TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Power-on Reset, Brown-out Reset ---- xxxx xxxx xxxx ---- 0000 N/A N/A N/A N/A N/A ---- xxxx xxxx xxxx ---x xxxx 0000 0000 xxxx xxxx 1111 1111 ---- ---0 --00 0101 ---- ---0 0--q 11qq xxxx xxxx xxxx xxxx 0-00 0000 0000 0000 1111 1111 -000 0000 xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000 MCLR Resets WDT Reset RESET Instruction Stack Resets ---- uuuu uuuu uuuu ---- 0000 N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu ---u uuuu uuuu uuuu uuuu uuuu 1111 1111 ---- ---0 --00 0101 ---- ---0 0--q qquu uuuu uuuu uuuu uuuu u-uu uuuu 0000 0000 1111 1111 -000 0000 uuuu uuuu 0000 0000 0000 0000 0000 0000 0000 0000 Wake-up via WDT or Interrupt ---- uuuu uuuu uuuu ---- uuuu N/A N/A N/A N/A N/A ---- uuuu uuuu uuuu ---u uuuu uuuu uuuu uuuu uuuu uuuu uuuu ---- ---u --uu uuuu ---- ---u u--u qquu uuuu uuuu uuuu uuuu u-uu uuuu uuuu uuuu 1111 1111 -uuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
Register
Applicable Devices
FSR1H FSR1L BSR INDF2 POSTINC2 POSTDEC2 PREINC2 PLUSW2 FSR2H FSR2L STATUS TMR0H TMR0L T0CON OSCCON LVDCON WDTCON RCON
(4)
242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242
442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442
252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252
452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452
TMR1H TMR1L T1CON TMR2 PR2 T2CON SSPBUF SSPADD SSPSTAT SSPCON1 SSPCON2
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read '0'. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read '0'.
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PIC18FXX2
TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Power-on Reset, Brown-out Reset xxxx xxxx xxxx xxxx 0000 00-0 00-- 0000 xxxx xxxx xxxx xxxx --00 0000 xxxx xxxx xxxx xxxx --00 0000 xxxx xxxx xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000 0000 -010 0000 000x 0000 0000 0000 0000 xx-0 x000 ---- ---MCLR Resets WDT Reset RESET Instruction Stack Resets uuuu uuuu uuuu uuuu 0000 00-0 00-- 0000 uuuu uuuu uuuu uuuu --00 0000 uuuu uuuu uuuu uuuu --00 0000 uuuu uuuu uuuu uuuu uuuu uuuu 0000 0000 0000 0000 0000 0000 0000 -010 0000 000x 0000 0000 0000 0000 uu-0 u000 ---- ---Wake-up via WDT or Interrupt uuuu uuuu uuuu uuuu uuuu uu-u uu-- uuuu uuuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu uuuu uuuu uuuu uuuu uuuu uu-0 u000 ---- ----
Register
Applicable Devices
ADRESH ADRESL ADCON0 ADCON1 CCPR1H CCPR1L CCP1CON CCPR2H CCPR2L CCP2CON TMR3H TMR3L T3CON SPBRG RCREG TXREG TXSTA RCSTA EEADR EEDATA EECON1 EECON2
242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242
442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442
252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252
452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read '0'. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read '0'.
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PIC18FXX2
TABLE 3-3: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Power-on Reset, Brown-out Reset ---1 1111 ---0 0000 ---0 0000 1111 1111 -111 1111 0000 0000 -000 0000 0000 0000 -000 0000 0000 -111 1111 1111 1111 1111 1111 1111 -111 1111(5) ---- -xxx xxxx xxxx xxxx xxxx xxxx xxxx -xxx xxxx(5) ---- -000 xxxx xxxx xxxx xxxx xxxx xxxx -x0x 0000(5) MCLR Resets WDT Reset RESET Instruction Stack Resets ---1 1111 ---0 0000 ---0 0000 1111 1111 -111 1111 0000 0000 -000 0000 0000 0000 -000 0000 0000 -111 1111 1111 1111 1111 1111 1111 -111 1111(5) ---- -uuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu(5) ---- -000 uuuu uuuu uuuu uuuu uuuu uuuu -u0u 0000(5) Wake-up via WDT or Interrupt ---u uuuu ---u uuuu(1) ---u uuuu uuuu uuuu -uuu uuuu uuuu uuuu(1) -uuu uuuu(1) uuuu uuuu -uuu uuuu uuuu -uuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu(5) ---- -uuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu(5) ---- -uuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu(5)
Register
Applicable Devices
IPR2 PIR2 PIE2 IPR1 PIR1 PIE1 TRISE TRISD TRISC TRISB TRISA(5,6) LATE LATD LATC LATB LATA
(5,6)
242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242 242
442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442 442
252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252 252
452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452 452
PORTE PORTD PORTC PORTB PORTA
(5,6)
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 4: See Table 3-2 for RESET value for specific condition. 5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other Oscillator modes, they are disabled and read '0'. 6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read '0'.
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PIC18FXX2
FIGURE 3-3:
VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD)
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 3-4:
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 3-5:
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
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PIC18FXX2
FIGURE 3-6: SLOW RISE TIME (MCLR TIED TO VDD)
5V VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET 0V 1V
FIGURE 3-7:
TIME-OUT SEQUENCE ON POR W/ PLL ENABLED (MCLR TIED TO VDD)
VDD MCLR IINTERNAL POR TPWRT PWRT TIME-OUT
TOST TPLL
OST TIME-OUT
PLL TIME-OUT INTERNAL RESET
Note:
TOST = 1024 clock cycles. TPLL 2 ms max. First three stages of the PWRT timer.
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PIC18FXX2
NOTES:
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PIC18FXX2
4.0 MEMORY ORGANIZATION
There are three memory blocks in Enhanced MCU devices. These memory blocks are: * Program Memory * Data RAM * Data EEPROM Data and program memory use separate busses, which allows for concurrent access of these blocks. Additional detailed information for FLASH program memory and Data EEPROM is provided in Section 5.0 and Section 6.0, respectively.
4.1
Program Memory Organization
A 21-bit program counter is capable of addressing the 2-Mbyte program memory space. Accessing a location between the physically implemented memory and the 2-Mbyte address will cause a read of all '0's (a NOP instruction). The PIC18F252 and PIC18F452 each have 32 Kbytes of FLASH memory, while the PIC18F242 and PIC18F442 have 16 Kbytes of FLASH. This means that PIC18FX52 devices can store up to 16K of single word instructions, and PIC18FX42 devices can store up to 8K of single word instructions. The RESET vector address is at 0000h and the interrupt vector addresses are at 0008h and 0018h. Figure 4-1 shows the Program Memory Map for PIC18F242/442 devices and Figure 4-2 shows the Program Memory Map for PIC18F252/452 devices.
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PIC18FXX2
FIGURE 4-1: PROGRAM MEMORY MAP AND STACK FOR PIC18F442/242 FIGURE 4-2: PROGRAM MEMORY MAP AND STACK FOR PIC18F452/252
PC<20:0> 21 CALL,RCALL,RETURN RETFIE,RETLW Stack Level 1
* * *
PC<20:0> 21 CALL,RCALL,RETURN RETFIE,RETLW Stack Level 1
* * *
Stack Level 31 RESET Vector 0000h
Stack Level 31 RESET Vector 0000h
High Priority Interrupt Vector 0008h Low Priority Interrupt Vector 0018h On-Chip Program Memory 3FFFh 4000h User Memory Space
High Priority Interrupt Vector 0008h Low Priority Interrupt Vector 0018h
7FFFh 8000h
Read '0'
Read '0'
1FFFFFh 200000h
1FFFFFh 200000h
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User Memory Space
On-Chip Program Memory
PIC18FXX2
4.2 Return Address Stack
4.2.2
The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC (Program Counter) is pushed onto the stack when a CALL or RCALL instruction is executed, or an interrupt is acknowledged. The PC value is pulled off the stack on a RETURN, RETLW or a RETFIE instruction. PCLATU and PCLATH are not affected by any of the RETURN or CALL instructions. The stack operates as a 31-word by 21-bit RAM and a 5-bit stack pointer, with the stack pointer initialized to 00000b after all RESETS. There is no RAM associated with stack pointer 00000b. This is only a RESET value. During a CALL type instruction, causing a push onto the stack, the stack pointer is first incremented and the RAM location pointed to by the stack pointer is written with the contents of the PC. During a RETURN type instruction, causing a pop from the stack, the contents of the RAM location pointed to by the STKPTR are transferred to the PC and then the stack pointer is decremented. The stack space is not part of either program or data space. The stack pointer is readable and writable, and the address on the top of the stack is readable and writable through SFR registers. Data can also be pushed to, or popped from, the stack using the top-of-stack SFRs. Status bits indicate if the stack pointer is at, or beyond the 31 levels provided.
RETURN STACK POINTER (STKPTR)
The STKPTR register contains the stack pointer value, the STKFUL (stack full) status bit, and the STKUNF (stack underflow) status bits. Register 4-1 shows the STKPTR register. The value of the stack pointer can be 0 through 31. The stack pointer increments when values are pushed onto the stack and decrements when values are popped off the stack. At RESET, the stack pointer value will be 0. The user may read and write the stack pointer value. This feature can be used by a Real Time Operating System for return stack maintenance. After the PC is pushed onto the stack 31 times (without popping any values off the stack), the STKFUL bit is set. The STKFUL bit can only be cleared in software or by a POR. The action that takes place when the stack becomes full depends on the state of the STVREN (Stack Overflow Reset Enable) configuration bit. Refer to Section 20.0 for a description of the device configuration bits. If STVREN is set (default), the 31st push will push the (PC + 2) value onto the stack, set the STKFUL bit, and reset the device. The STKFUL bit will remain set and the stack pointer will be set to `0'. If STVREN is cleared, the STKFUL bit will be set on the 31st push and the stack pointer will increment to 31. Any additional pushes will not overwrite the 31st push, and STKPTR will remain at 31. When the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the PC and sets the STKUNF bit, while the stack pointer remains at 0. The STKUNF bit will remain set until cleared in software or a POR occurs. Note: Returning a value of zero to the PC on an underflow has the effect of vectoring the program to the RESET vector, where the stack conditions can be verified and appropriate actions can be taken.
4.2.1
TOP-OF-STACK ACCESS
The top of the stack is readable and writable. Three register locations, TOSU, TOSH and TOSL hold the contents of the stack location pointed to by the STKPTR register. This allows users to implement a software stack if necessary. After a CALL, RCALL or interrupt, the software can read the pushed value by reading the TOSU, TOSH and TOSL registers. These values can be placed on a user defined software stack. At return time, the software can replace the TOSU, TOSH and TOSL and do a return. The user must disable the global interrupt enable bits during this time to prevent inadvertent stack operations.
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PIC18FXX2
REGISTER 4-1: STKPTR REGISTER
R/C-0 STKOVF bit 7 bit 7(1) STKOVF: Stack Full Flag bit 1 = Stack became full or overflowed 0 = Stack has not become full or overflowed STKUNF: Stack Underflow Flag bit 1 = Stack underflow occurred 0 = Stack underflow did not occur Unimplemented: Read as '0' SP4:SP0: Stack Pointer Location bits Note 1: Bit 7 and bit 6 can only be cleared in user software or by a POR. Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/C-0 STKUNF U-0 -- R/W-0 SP4 R/W-0 SP3 R/W-0 SP2 R/W-0 SP1 R/W-0 SP0 bit 0
bit 6(1)
bit 5 bit 4-0
FIGURE 4-3:
RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
Return Address Stack 11111 11110 11101 TOSU 0x00 TOSH 0x1A TOSL 0x34 Top of Stack 00011 0x001A34 00010 0x000D58 00001 00000 STKPTR<4:0> 00010
4.2.3
PUSH AND POP INSTRUCTIONS
4.2.4
STACK FULL/UNDERFLOW RESETS
Since the Top-of-Stack (TOS) is readable and writable, the ability to push values onto the stack and pull values off the stack without disturbing normal program execution is a desirable option. To push the current PC value onto the stack, a PUSH instruction can be executed. This will increment the stack pointer and load the current PC value onto the stack. TOSU, TOSH and TOSL can then be modified to place a return address on the stack. The ability to pull the TOS value off of the stack and replace it with the value that was previously pushed onto the stack, without disturbing normal execution, is achieved by using the POP instruction. The POP instruction discards the current TOS by decrementing the stack pointer. The previous value pushed onto the stack then becomes the TOS value.
These resets are enabled by programming the STVREN configuration bit. When the STVREN bit is disabled, a full or underflow condition will set the appropriate STKFUL or STKUNF bit, but not cause a device RESET. When the STVREN bit is enabled, a full or underflow will set the appropriate STKFUL or STKUNF bit and then cause a device RESET. The STKFUL or STKUNF bits are only cleared by the user software or a POR Reset.
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PIC18FXX2
4.3 Fast Register Stack 4.4 PCL, PCLATH and PCLATU
A "fast interrupt return" option is available for interrupts. A Fast Register Stack is provided for the STATUS, WREG and BSR registers and are only one in depth. The stack is not readable or writable and is loaded with the current value of the corresponding register when the processor vectors for an interrupt. The values in the registers are then loaded back into the working registers, if the FAST RETURN instruction is used to return from the interrupt. A low or high priority interrupt source will push values into the stack registers. If both low and high priority interrupts are enabled, the stack registers cannot be used reliably for low priority interrupts. If a high priority interrupt occurs while servicing a low priority interrupt, the stack register values stored by the low priority interrupt will be overwritten. If high priority interrupts are not disabled during low priority interrupts, users must save the key registers in software during a low priority interrupt. If no interrupts are used, the fast register stack can be used to restore the STATUS, WREG and BSR registers at the end of a subroutine call. To use the fast register stack for a subroutine call, a FAST CALL instruction must be executed. Example 4-1 shows a source code example that uses the fast register stack. The program counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21-bits wide. The low byte is called the PCL register. This register is readable and writable. The high byte is called the PCH register. This register contains the PC<15:8> bits and is not directly readable or writable. Updates to the PCH register may be performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits and is not directly readable or writable. Updates to the PCU register may be performed through the PCLATU register. The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the LSB of PCL is fixed to a value of '0'. The PC increments by 2 to address sequential instructions in the program memory. The CALL, RCALL, GOTO and program branch instructions write to the program counter directly. For these instructions, the contents of PCLATH and PCLATU are not transferred to the program counter. The contents of PCLATH and PCLATU will be transferred to the program counter by an operation that writes PCL. Similarly, the upper two bytes of the program counter will be transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 4.8.1).
EXAMPLE 4-1:
CALL SUB1, FAST
FAST REGISTER STACK CODE EXAMPLE
;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK
4.5
Clocking Scheme/Instruction Cycle
* * SUB1 * * * RETURN FAST
;RESTORE VALUES SAVED ;IN FAST REGISTER STACK
The clock input (from OSC1) is internally divided by four to generate four non-overlapping quadrature clocks, namely Q1, Q2, Q3 and Q4. Internally, the program counter (PC) is incremented every Q1, the instruction is fetched from the program memory and latched into the instruction register in Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 4-4.
FIGURE 4-4:
OSC1 Q1 Q2 Q3 Q4 PC OSC2/CLKO (RC mode)
CLOCK/INSTRUCTION CYCLE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Internal Phase Clock
PC
PC+2
PC+4
Execute INST (PC-2) Fetch INST (PC)
Execute INST (PC) Fetch INST (PC+2)
Execute INST (PC+2) Fetch INST (PC+4)
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PIC18FXX2
4.6 Instruction Flow/Pipelining
An "Instruction Cycle" consists of four Q cycles (Q1, Q2, Q3 and Q4). The instruction fetch and execute are pipelined such that fetch takes one instruction cycle, while decode and execute takes another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g., GOTO) then two cycles are required to complete the instruction (Example 4-2). A fetch cycle begins with the program counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the "Instruction Register" (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3, and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write).
EXAMPLE 4-2:
INSTRUCTION PIPELINE FLOW
TCY0 TCY1 Execute 1 Fetch 2 Execute 2 Fetch 3 Execute 3 Fetch 4 Flush (NOP) Fetch SUB_1 Execute SUB_1 TCY2 TCY3 TCY4 TCY5
1. MOVLW 55h 2. MOVWF PORTB 3. BRA 4. BSF SUB_1
Fetch 1
PORTA, BIT3 (Forced NOP)
5. Instruction @ address SUB_1
All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction is "flushed" from the pipeline while the new instruction is being fetched and then executed.
4.7
Instructions in Program Memory
The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program memory. The Least Significant Byte of an instruction word is always stored in a program memory location with an even address (LSB ='0'). Figure 4-5 shows an example of how instruction words are stored in the program memory. To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSB will always read '0' (see Section 4.4).
The CALL and GOTO instructions have an absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, the data contained in the instruction is a word address. The word address is written to PC<20:1>, which accesses the desired byte address in program memory. Instruction #2 in Figure 4-5 shows how the instruction "GOTO 000006h' is encoded in the program memory. Program branch instructions which encode a relative address offset operate in the same manner. The offset value stored in a branch instruction represents the number of single word instructions that the PC will be offset by. Section 20.0 provides further details of the instruction set.
FIGURE 4-5:
INSTRUCTIONS IN PROGRAM MEMORY
LSB = 1 Program Memory Byte Locations LSB = 0 Word Address 000000h 000002h 000004h 000006h 000008h 00000Ah 00000Ch 00000Eh 000010h 000012h 000014h
Instruction 1: Instruction 2: Instruction 3:
MOVLW GOTO MOVFF
055h 000006h 123h, 456h
0Fh EFh F0h C1h F4h
55h 03h 00h 23h 56h
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2002 Microchip Technology Inc.
PIC18FXX2
4.7.1 TWO-WORD INSTRUCTIONS
The PIC18FXX2 devices have four two-word instructions: MOVFF, CALL, GOTO and LFSR. The second word of these instructions has the 4 MSBs set to 1's and is a special kind of NOP instruction. The lower 12 bits of the second word contain data to be used by the instruction. If the first word of the instruction is executed, the data in the second word is accessed. If the second word of the instruction is executed by itself (first word was skipped), it will execute as a NOP. This action is necessary when the two-word instruction is preceded by a conditional instruction that changes the PC. A program example that demonstrates this concept is shown in Example 4-3. Refer to Section 20.0 for further details of the instruction set.
EXAMPLE 4-3:
CASE 1: Object Code
TWO-WORD INSTRUCTIONS
Source Code TSTFSZ MOVFF ADDWF REG1 ; is RAM location 0? ; 2nd operand holds address of REG2 REG3 ; continue code REG1, REG2 ; No, execute 2-word instruction
0110 0110 0000 0000 1100 0001 0010 0011 1111 0100 0101 0110 0010 0100 0000 0000 CASE 2: Object Code 0110 0110 0000 0000 1100 0001 0010 0011 1111 0100 0101 0110 0010 0100 0000 0000
Source Code TSTFSZ MOVFF ADDWF REG1 ; is RAM location 0? ; 2nd operand becomes NOP REG3 ; continue code REG1, REG2 ; Yes
4.8
Lookup Tables
4.8.2
TABLE READS/TABLE WRITES
Lookup tables are implemented two ways. These are: * Computed GOTO * Table Reads
A better method of storing data in program memory allows 2 bytes of data to be stored in each instruction location. Lookup table data may be stored 2 bytes per program word by using table reads and writes. The table pointer (TBLPTR) specifies the byte address and the table latch (TABLAT) contains the data that is read from, or written to program memory. Data is transferred to/from program memory, one byte at a time. A description of the Table Read/Table Write operation is shown in Section 3.0.
4.8.1
COMPUTED GOTO
A computed GOTO is accomplished by adding an offset to the program counter (ADDWF PCL). A lookup table can be formed with an ADDWF PCL instruction and a group of RETLW 0xnn instructions. WREG is loaded with an offset into the table before executing a call to that table. The first instruction of the called routine is the ADDWF PCL instruction. The next instruction executed will be one of the RETLW 0xnn instructions, that returns the value 0xnn to the calling function. The offset value (value in WREG) specifies the number of bytes that the program counter should advance. In this method, only one data byte may be stored in each instruction location and room on the return address stack is required. Note: The ADDWF PCL instruction does not update PCLATH and PCLATU. A read operation on PCL must be performed to update PCLATH and PCLATU.
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DS39564B-page 41
PIC18FXX2
4.9 Data Memory Organization
4.9.1
The data memory is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. Figure 4-6 and Figure 4-7 show the data memory organization for the PIC18FXX2 devices. The data memory map is divided into as many as 16 banks that contain 256 bytes each. The lower 4 bits of the Bank Select Register (BSR<3:0>) select which bank will be accessed. The upper 4 bits for the BSR are not implemented. The data memory contains Special Function Registers (SFR) and General Purpose Registers (GPR). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratch pad operations in the user's application. The SFRs start at the last location of Bank 15 (0xFFF) and extend downwards. Any remaining space beyond the SFRs in the Bank may be implemented as GPRs. GPRs start at the first location of Bank 0 and grow upwards. Any read of an unimplemented location will read as '0's. The entire data memory may be accessed directly or indirectly. Direct addressing may require the use of the BSR register. Indirect addressing requires the use of a File Select Register (FSRn) and a corresponding Indirect File Operand (INDFn). Each FSR holds a 12-bit address value that can be used to access any location in the Data Memory map without banking. The instruction set and architecture allow operations across all banks. This may be accomplished by indirect addressing or by the use of the MOVFF instruction. The MOVFF instruction is a two-word/two-cycle instruction that moves a value from one register to another. To ensure that commonly used registers (SFRs and select GPRs) can be accessed in a single cycle, regardless of the current BSR values, an Access Bank is implemented. A segment of Bank 0 and a segment of Bank 15 comprise the Access RAM. Section 4.10 provides a detailed description of the Access RAM.
GENERAL PURPOSE REGISTER FILE
The register file can be accessed either directly or indirectly. Indirect addressing operates using a File Select Register and corresponding Indirect File Operand. The operation of indirect addressing is shown in Section 4.12. Enhanced MCU devices may have banked memory in the GPR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other RESETS. Data RAM is available for use as GPR registers by all instructions. The top half of Bank 15 (0xF80 to 0xFFF) contains SFRs. All other banks of data memory contain GPR registers, starting with Bank 0.
4.9.2
SPECIAL FUNCTION REGISTERS
The Special Function Registers (SFRs) are registers used by the CPU and Peripheral Modules for controlling the desired operation of the device. These registers are implemented as static RAM. A list of these registers is given in Table 4-1 and Table 4-2. The SFRs can be classified into two sets; those associated with the "core" function and those related to the peripheral functions. Those registers related to the "core" are described in this section, while those related to the operation of the peripheral features are described in the section of that peripheral feature. The SFRs are typically distributed among the peripherals whose functions they control. The unused SFR locations will be unimplemented and read as '0's. See Table 4-1 for addresses for the SFRs.
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PIC18FXX2
FIGURE 4-6:
BSR<3:0> = 0000 00h Bank 0 FFh 00h Bank 1 FFh 00h Bank 2 FFh GPR 2FFh 300h
DATA MEMORY MAP FOR PIC18F242/442
Data Memory Map Access RAM GPR GPR 1FFh 200h 000h 07Fh 080h 0FFh 100h
= 0001
= 0010
Access Bank 7Fh Access RAM high 80h (SFRs) FFh Access RAM low 00h
= 0011 = 1110
Bank 3 to Bank 14
Unused Read '00h'
= 1111
00h Bank 15 FFh
Unused SFR
EFFh F00h F7Fh F80h FFFh
When a = 0, the BSR is ignored and the Access Bank is used. The first 128 bytes are General Purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15).
When a = 1, the BSR is used to specify the RAM location that the instruction uses.
2002 Microchip Technology Inc.
DS39564B-page 43
PIC18FXX2
FIGURE 4-7:
BSR<3:0> = 0000 00h Bank 0 FFh 00h Bank 1 FFh 00h Bank 2 FFh 00h Bank 3 FFh = 0100 Bank 4 00h Bank 5 FFh GPR 5FFh 600h GPR 4FFh 500h GPR 3FFh 400h Access Bank 7Fh Access RAM high 80h (SFR's) FFh Access RAM low 00h
DATA MEMORY MAP FOR PIC18F252/452
Data Memory Map Access RAM GPR GPR 1FFh 200h GPR 2FFh 300h 000h 07Fh 080h 0FFh 100h
= 0001
= 0010
= 0011
= 0101
= 0110 = 1110
Bank 6 to Bank 14
Unused Read '00h'
= 1111
00h Bank 15 FFh
Unused SFR
EFFh F00h F7Fh F80h FFFh
When a = 0, the BSR is ignored and the Access Bank is used. The first 128 bytes are General Purpose RAM (from Bank 0). The second 128 bytes are Special Function Registers (from Bank 15).
When a = 1, the BSR is used to specify the RAM location that the instruction uses.
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2002 Microchip Technology Inc.
PIC18FXX2
TABLE 4-1:
Address FFFh FFEh FFDh FFCh FFBh FFAh FF9h FF8h FF7h FF6h FF5h FF4h FF3h FF2h FF1h FF0h FEFh FEEh FEDh FECh FEBh FEAh FE9h FE8h FE7h FE6h FE5h FE4h FE3h FE2h FE1h FE0h
SPECIAL FUNCTION REGISTER MAP
Name TOSU TOSH TOSL STKPTR PCLATU PCLATH PCL TBLPTRU TBLPTRH TBLPTRL TABLAT PRODH PRODL INTCON INTCON2 INTCON3 INDF0(3) POSTINC0(3) Address FDFh FDEh FDDh FDCh FDBh FDAh FD9h FD8h FD7h FD6h FD5h FD4h FD3h FD2h FD1h FD0h FCFh FCEh FCDh FCCh FCBh FCAh FC9h FC8h FC7h FC6h FC5h FC4h FC3h FC2h FC1h FC0h Name INDF2(3) POSTINC2(3) POSTDEC2(3) PREINC2 FSR2H FSR2L STATUS TMR0H TMR0L T0CON -- OSCCON LVDCON WDTCON RCON TMR1H TMR1L T1CON TMR2 PR2 T2CON SSPBUF SSPADD SSPSTAT SSPCON1 SSPCON2 ADRESH ADRESL ADCON0 ADCON1 --
(3)
Address FBFh FBEh FBDh FBCh FBBh FBAh FB9h FB8h FB7h FB6h FB5h FB4h FB3h FB2h FB1h FB0h FAFh FAEh FADh FACh FABh FAAh FA9h FA8h FA7h FA6h FA5h FA4h FA3h FA2h FA1h FA0h
Name CCPR1H CCPR1L CCP1CON CCPR2H CCPR2L CCP2CON -- -- -- -- -- -- TMR3H TMR3L T3CON -- SPBRG RCREG TXREG TXSTA RCSTA -- EEADR EEDATA EECON2 EECON1 -- -- -- IPR2 PIR2 PIE2
Address F9Fh F9Eh F9Dh F9Ch F9Bh F9Ah F99h F98h F97h F96h F95h F94h F93h F92h F91h F90h F8Fh F8Eh F8Dh F8Ch F8Bh F8Ah F89h F88h F87h F86h F85h F84h F83h F82h F81h F80h
Name IPR1 PIR1 PIE1 -- -- -- -- -- -- TRISE(2) TRISD(2) TRISC TRISB TRISA -- -- -- -- LATE(2) LATD(2) LATC LATB LATA -- -- -- -- PORTE(2) PORTD(2) PORTC PORTB PORTA
PLUSW2(3)
POSTDEC0(3) PREINC0(3) PLUSW0(3) FSR0H FSR0L WREG INDF1(3) POSTINC1(3) POSTDEC1(3) PREINC1 FSR1H FSR1L BSR
(3)
PLUSW1(3)
Note 1: Unimplemented registers are read as '0'. 2: This register is not available on PIC18F2X2 devices. 3: This is not a physical register.
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DS39564B-page 45
PIC18FXX2
TABLE 4-2:
File Name TOSU TOSH TOSL STKPTR PCLATU PCLATH PCL TBLPTRU TBLPTRH TBLPTRL TABLAT PRODH PRODL INTCON INTCON2 INTCON3 INDF0
REGISTER FILE SUMMARY
Bit 7 -- Bit 6 -- Bit 5 -- Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on Details POR, BOR on page:
---0 0000 0000 0000 0000 0000
Top-of-Stack upper Byte (TOS<20:16>)
37 37 37 38 39 39 39 58 58 58 58 71 71 75 76 77 50 50 50 50 50 50 50 n/a 50 50 50 50 50 50 50 49 50 50 50 50 50 50 50 52 105 105 103
Top-of-Stack High Byte (TOS<15:8>) Top-of-Stack Low Byte (TOS<7:0>) STKFUL -- STKUNF -- -- -- Return Stack Pointer Holding Register for PC<20:16>
00-0 0000 ---0 0000 0000 0000 0000 0000
Holding Register for PC<15:8> PC Low Byte (PC<7:0>) -- -- bit21(2) Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
--00 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx xxxx xxxx
Program Memory Table Pointer High Byte (TBLPTR<15:8>) Program Memory Table Pointer Low Byte (TBLPTR<7:0>) Program Memory Table Latch Product Register High Byte Product Register Low Byte GIE/GIEH RBPU INT2IP PEIE/GIEL INTEDG0 INT1IP TMR0IE INTEDG1 -- INT0IE INTEDG2 INT2IE RBIE -- INT1IE TMR0IF TMR0IP -- INT0IF -- INT2IF RBIF RBIP INT1IF
0000 000x 1111 -1-1 11-0 0-00
Uses contents of FSR0 to address data memory - value of FSR0 not changed (not a physical register)
n/a n/a n/a n/a n/a
POSTINC0 Uses contents of FSR0 to address data memory - value of FSR0 post-incremented (not a physical register) POSTDEC0 Uses contents of FSR0 to address data memory - value of FSR0 post-decremented (not a physical register) PREINC0 PLUSW0 FSR0H FSR0L WREG INDF1 Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register) Uses contents of FSR0 to address data memory - value of FSR0 (not a physical register). Offset by value in WREG. -- Working Register Uses contents of FSR1 to address data memory - value of FSR1 not changed (not a physical register) -- -- -- Indirect Data Memory Address Pointer 0 Low Byte
Indirect Data Memory Address Pointer 0 High Byte ---- 0000
xxxx xxxx xxxx xxxx
n/a n/a n/a n/a n/a
POSTINC1 Uses contents of FSR1 to address data memory - value of FSR1 post-incremented (not a physical register) POSTDEC1 Uses contents of FSR1 to address data memory - value of FSR1 post-decremented (not a physical register) PREINC1 PLUSW1 FSR1H FSR1L BSR INDF2 Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register) Uses contents of FSR1 to address data memory - value of FSR1 (not a physical register). Offset by value in WREG. -- -- -- -- -- -- -- -- Indirect Data Memory Address Pointer 1 Low Byte Bank Select Register Uses contents of FSR2 to address data memory - value of FSR2 not changed (not a physical register)
Indirect Data Memory Address Pointer 1 High Byte ---- 0000
xxxx xxxx ---- 0000
n/a n/a n/a n/a n/a
POSTINC2 Uses contents of FSR2 to address data memory - value of FSR2 post-incremented (not a physical register) POSTDEC2 Uses contents of FSR2 to address data memory - value of FSR2 post-decremented (not a physical register) PREINC2 PLUSW2 FSR2H FSR2L STATUS TMR0H TMR0L T0CON Legend: Note 1: 2: 3: Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register) Uses contents of FSR2 to address data memory - value of FSR2 (not a physical register). Offset by value in WREG. -- -- -- -- -- -- -- N Indirect Data Memory Address Pointer 2 Low Byte OV Z DC C Timer0 Register High Byte Timer0 Register Low Byte TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0
Indirect Data Memory Address Pointer 2 High Byte ---- 0000
xxxx xxxx ---x xxxx 0000 0000 xxxx xxxx 1111 1111
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes. Bit 21 of the TBLPTRU allows access to the device configuration bits. These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.
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PIC18FXX2
TABLE 4-2:
File Name OSCCON LVDCON WDTCON RCON TMR1H TMR1L T1CON TMR2 PR2 T2CON SSPBUF SSPADD SSPSTAT SSPCON1 SSPCON2 ADRESH ADRESL ADCON0 ADCON1 CCPR1H CCPR1L CCP1CON CCPR2H CCPR2L CCP2CON TMR3H TMR3L T3CON SPBRG RCREG TXREG TXSTA RCSTA EEADR EEDATA EECON2 EECON1 Legend: Note 1: 2: 3:
REGISTER FILE SUMMARY (CONTINUED)
Bit 7 -- -- -- IPEN Bit 6 -- -- -- -- Bit 5 -- IRVST -- -- Bit 4 -- LVDEN -- RI Bit 3 -- LVDL3 -- TO Bit 2 -- LVDL2 -- PD Bit 1 -- LVDL1 -- POR Bit 0 SCS LVDL0 SWDTE BOR Value on Details POR, BOR on page:
---- ---0 --00 0101 ---- ---0
21 191 203
0--1 11qq 53, 28, 84 xxxx xxxx xxxx xxxx
Timer1 Register High Byte Timer1 Register Low Byte RD16 Timer2 Register Timer2 Period Register -- TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 SSP Receive Buffer/Transmit Register SSP Address Register in I2C Slave mode. SSP Baud Rate Reload Register in I2C Master mode. SMP WCOL GCEN CKE SSPOV ACKSTAT D/A SSPEN ACKDT P CKP ACKEN S SSPM3 RCEN R/W SSPM2 PEN UA SSPM1 RSEN BF SSPM0 SEN -- T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS
107 107 107 111 112 111 125 134 126 127 137
TMR1ON 0-00 0000
0000 0000 1111 1111
T2CKPS0 -000 0000
xxxx xxxx 0000 0000 0000 0000 0000 0000 0000 0000
A/D Result Register High Byte A/D Result Register Low Byte ADCS1 ADFM ADCS0 ADCS2 CHS2 -- CHS1 -- CHS0 PCFG3 GO/DONE PCFG2 -- PCFG1 ADON PCFG0
xxxx xxxx 187,188 xxxx xxxx 187,188 0000 00-0 00-- 0000
181 182
Capture/Compare/PWM Register1 High Byte Capture/Compare/PWM Register1 Low Byte -- -- DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 Capture/Compare/PWM Register2 High Byte Capture/Compare/PWM Register2 Low Byte -- -- DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 Timer3 Register High Byte Timer3 Register Low Byte RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS
xxxx xxxx 121, 123 xxxx xxxx 121, 123 --00 0000
117
xxxx xxxx 121, 123 xxxx xxxx 121, 123 --00 0000 xxxx xxxx xxxx xxxx
117 113 113 113 168
TMR3ON 0000 0000
0000 0000
USART1 Baud Rate Generator USART1 Receive Register USART1 Transmit Register CSRC SPEN TX9 RX9 TXEN SREN SYNC CREN -- ADDEN BRGH FERR TRMT OERR TX9D RX9D
0000 0000 175, 178, 180 0000 0000 173, 176, 179 0000 -010 0000 000x 0000 0000 0000 0000 ---- ----
166 167 65, 69 69 65, 69 66
Data EEPROM Address Register Data EEPROM Data Register Data EEPROM Control Register 2 (not a physical register) EEPGD CFGS -- FREE WRERR WREN WR RD
xx-0 x000
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes. Bit 21 of the TBLPTRU allows access to the device configuration bits. These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.
2002 Microchip Technology Inc.
DS39564B-page 47
PIC18FXX2
TABLE 4-2:
File Name IPR2 PIR2 PIE2 IPR1 PIR1 PIE1 TRISE(3) TRISD(3) TRISC TRISB TRISA LATE(3) LATD(3) LATC LATB LATA PORTE(3) PORTD PORTC PORTB PORTA Legend: Note 1: 2: 3:
(3)
REGISTER FILE SUMMARY (CONTINUED)
Bit 7 -- -- -- Bit 6 -- -- -- ADIP ADIF ADIE OBF Bit 5 -- -- -- RCIP RCIF RCIE IBOV Bit 4 EEIP EEIF EEIE TXIP TXIF TXIE PSPMODE Bit 3 BCLIP BCLIF BCLIE SSPIP SSPIF SSPIE -- Bit 2 LVDIP LVDIF LVDIE CCP1IP CCP1IF CCP1IE Bit 1 TMR3IP TMR3IF TMR3IE TMR2IP TMR2IF TMR2IE Bit 0 CCP2IP CCP2IF CCP2IE TMR1IP TMR1IF TMR1IE Value on Details POR, BOR on page:
---1 1111 ---0 0000 ---0 0000 1111 1111 0000 0000 0000 0000 0000 -111 1111 1111 1111 1111 1111 1111 -111 1111 ---- -xxx xxxx xxxx xxxx xxxx xxxx xxxx
83 79 81 82 78 80 98 96 93 90 87 99 95 93 90 87 99 95 93 90 87
PSPIP(3) PSPIF(3) PSPIE IBF
(3)
Data Direction bits for PORTE
Data Direction Control Register for PORTD Data Direction Control Register for PORTC Data Direction Control Register for PORTB -- -- TRISA6(1) Data Direction Control Register for PORTA -- -- -- -- Read PORTE Data Latch, Write PORTE Data Latch
Read PORTD Data Latch, Write PORTD Data Latch Read PORTC Data Latch, Write PORTC Data Latch Read PORTB Data Latch, Write PORTB Data Latch -- LATA6(1) Read PORTA Data Latch, Write PORTA Data Latch(1)
-xxx xxxx ---- -000 xxxx xxxx xxxx xxxx xxxx xxxx -x0x 0000
Read PORTE pins, Write PORTE Data Latch Read PORTD pins, Write PORTD Data Latch Read PORTC pins, Write PORTC Data Latch Read PORTB pins, Write PORTB Data Latch -- RA6(1) Read PORTA pins, Write PORTA Data Latch(1)
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes. Bit 21 of the TBLPTRU allows access to the device configuration bits. These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.
DS39564B-page 48
2002 Microchip Technology Inc.
PIC18FXX2
4.10 Access Bank 4.11 Bank Select Register (BSR)
The Access Bank is an architectural enhancement which is very useful for C compiler code optimization. The techniques used by the C compiler may also be useful for programs written in assembly. This data memory region can be used for: * * * * * Intermediate computational values Local variables of subroutines Faster context saving/switching of variables Common variables Faster evaluation/control of SFRs (no banking) The need for a large general purpose memory space dictates a RAM banking scheme. The data memory is partitioned into sixteen banks. When using direct addressing, the BSR should be configured for the desired bank. BSR<3:0> holds the upper 4 bits of the 12-bit RAM address. The BSR<7:4> bits will always read '0's, and writes will have no effect. A MOVLB instruction has been provided in the instruction set to assist in selecting banks. If the currently selected bank is not implemented, any read will return all '0's and all writes are ignored. The STATUS register bits will be set/cleared as appropriate for the instruction performed. Each Bank extends up to FFh (256 bytes). All data memory is implemented as static RAM. A MOVFF instruction ignores the BSR, since the 12-bit addresses are embedded into the instruction word. Section 4.12 provides a description of indirect addressing, which allows linear addressing of the entire RAM space.
The Access Bank is comprised of the upper 128 bytes in Bank 15 (SFRs) and the lower 128 bytes in Bank 0. These two sections will be referred to as Access RAM High and Access RAM Low, respectively. Figure 4-6 and Figure 4-7 indicate the Access RAM areas. A bit in the instruction word specifies if the operation is to occur in the bank specified by the BSR register or in the Access Bank. This bit is denoted by the 'a' bit (for access bit). When forced in the Access Bank (a = 0), the last address in Access RAM Low is followed by the first address in Access RAM High. Access RAM High maps the Special Function registers, so that these registers can be accessed without any software overhead. This is useful for testing status flags and modifying control bits.
FIGURE 4-8:
DIRECT ADDRESSING
Direct Addressing
BSR<3:0> 7 From Opcode(3) 0
Bank Select(2)
Location Select(3) 00h 000h 01h 100h 0Eh E00h 0Fh F00h
Data Memory(1)
0FFh
1FFh
EFFh
FFFh
Bank 0
Note 1: For register file map detail, see Table 4-1.
Bank 1
Bank 14
Bank 15
2: The access bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the registers of the Access Bank. 3: The MOVFF instruction embeds the entire 12-bit address in the instruction.
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DS39564B-page 49
PIC18FXX2
4.12 Indirect Addressing, INDF and FSR Registers
the data from the address pointed to by FSR1H:FSR1L. INDFn can be used in code anywhere an operand can be used. If INDF0, INDF1 or INDF2 are read indirectly via an FSR, all '0's are read (zero bit is set). Similarly, if INDF0, INDF1 or INDF2 are written to indirectly, the operation will be equivalent to a NOP instruction and the STATUS bits are not affected.
Indirect addressing is a mode of addressing data memory, where the data memory address in the instruction is not fixed. An FSR register is used as a pointer to the data memory location that is to be read or written. Since this pointer is in RAM, the contents can be modified by the program. This can be useful for data tables in the data memory and for software stacks. Figure 4-9 shows the operation of indirect addressing. This shows the moving of the value to the data memory address specified by the value of the FSR register. Indirect addressing is possible by using one of the INDF registers. Any instruction using the INDF register actually accesses the register pointed to by the File Select Register, FSR. Reading the INDF register itself, indirectly (FSR = 0), will read 00h. Writing to the INDF register indirectly, results in a no operation. The FSR register contains a 12-bit address, which is shown in Figure 4-10. The INDFn register is not a physical register. Addressing INDFn actually addresses the register whose address is contained in the FSRn register (FSRn is a pointer). This is indirect addressing. Example 4-4 shows a simple use of indirect addressing to clear the RAM in Bank1 (locations 100h-1FFh) in a minimum number of instructions.
4.12.1
INDIRECT ADDRESSING OPERATION
Each FSR register has an INDF register associated with it, plus four additional register addresses. Performing an operation on one of these five registers determines how the FSR will be modified during indirect addressing. When data access is done to one of the five INDFn locations, the address selected will configure the FSRn register to: * Do nothing to FSRn after an indirect access (no change) - INDFn * Auto-decrement FSRn after an indirect access (post-decrement) - POSTDECn * Auto-increment FSRn after an indirect access (post-increment) - POSTINCn * Auto-increment FSRn before an indirect access (pre-increment) - PREINCn * Use the value in the WREG register as an offset to FSRn. Do not modify the value of the WREG or the FSRn register after an indirect access (no change) - PLUSWn When using the auto-increment or auto-decrement features, the effect on the FSR is not reflected in the STATUS register. For example, if the indirect address causes the FSR to equal '0', the Z bit will not be set. Incrementing or decrementing an FSR affects all 12 bits. That is, when FSRnL overflows from an increment, FSRnH will be incremented automatically. Adding these features allows the FSRn to be used as a stack pointer, in addition to its uses for table operations in data memory. Each FSR has an address associated with it that performs an indexed indirect access. When a data access to this INDFn location (PLUSWn) occurs, the FSRn is configured to add the signed value in the WREG register and the value in FSR to form the address before an indirect access. The FSR value is not changed. If an FSR register contains a value that points to one of the INDFn, an indirect read will read 00h (zero bit is set), while an indirect write will be equivalent to a NOP (STATUS bits are not affected). If an indirect addressing operation is done where the target address is an FSRnH or FSRnL register, the write operation will dominate over the pre- or post-increment/decrement functions.
EXAMPLE 4-4:
HOW TO CLEAR RAM (BANK1) USING INDIRECT ADDRESSING
NEXT
FSR0 ,0x100 ; POSTINC0 ; Clear INDF ; register and ; inc pointer BTFSS FSR0H, 1 ; All done with ; Bank1? GOTO NEXT ; NO, clear next CONTINUE ; YES, continue
LFSR CLRF
There are three indirect addressing registers. To address the entire data memory space (4096 bytes), these registers are 12-bit wide. To store the 12-bits of addressing information, two 8-bit registers are required. These indirect addressing registers are: 1. 2. 3. FSR0: composed of FSR0H:FSR0L FSR1: composed of FSR1H:FSR1L FSR2: composed of FSR2H:FSR2L
In addition, there are registers INDF0, INDF1 and INDF2, which are not physically implemented. Reading or writing to these registers activates indirect addressing, with the value in the corresponding FSR register being the address of the data. If an instruction writes a value to INDF0, the value will be written to the address pointed to by FSR0H:FSR0L. A read from INDF1 reads
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FIGURE 4-9: INDIRECT ADDRESSING OPERATION
RAM 0h
Instruction Executed Opcode Address FFFh 12 File Address = access of an indirect addressing register
BSR<3:0> Instruction Fetched Opcode 4
12 8 File
12
FSR
FIGURE 4-10:
INDIRECT ADDRESSING
Indirect Addressing
11 FSR Register 0
Location Select
0000h
Data Memory(1)
0FFFh Note 1: For register file map detail, see Table 4-1.
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4.13 STATUS Register
The STATUS register, shown in Register 4-2, contains the arithmetic status of the ALU. The STATUS register can be the destination for any instruction, as with any other register. If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV, or N bits, then the write to these five bits is disabled. These bits are set or cleared according to the device logic. Therefore, the result of an instruction with the STATUS register as destination may be different than intended. For example, CLRF STATUS will clear the upper three bits and set the Z bit. This leaves the STATUS register as 000u u1uu (where u = unchanged). It is recommended, therefore, that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the STATUS register, because these instructions do not affect the Z, C, DC, OV, or N bits from the STATUS register. For other instructions not affecting any status bits, see Table 20-2. Note: The C and DC bits operate as a borrow and digit borrow bit respectively, in subtraction.
REGISTER 4-2:
STATUS REGISTER
U-0 -- bit 7 U-0 -- U-0 -- R/W-x N R/W-x OV R/W-x Z R/W-x DC R/W-x C bit 0
bit 7-5 bit 4
Unimplemented: Read as '0' N: Negative bit This bit is used for signed arithmetic (2's complement). It indicates whether the result was negative (ALU MSB = 1). 1 = Result was negative 0 = Result was positive OV: Overflow bit This bit is used for signed arithmetic (2's complement). It indicates an overflow of the 7-bit magnitude, which causes the sign bit (bit7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero DC: Digit carry/borrow bit For ADDWF, ADDLW, SUBLW, and SUBWF instructions 1 = A carry-out from the 4th low order bit of the result occurred 0 = No carry-out from the 4th low order bit of the result Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the bit 4 or bit 3 of the source register.
bit 3
bit 2
bit 1
bit 0
C: Carry/borrow bit For ADDWF, ADDLW, SUBLW, and SUBWF instructions 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low order bit of the source register.
Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
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4.14 RCON Register
The Reset Control (RCON) register contains flag bits that allow differentiation between the sources of a device RESET. These flags include the TO, PD, POR, BOR and RI bits. This register is readable and writable. Note 1: If the BOREN configuration bit is set (Brown-out Reset enabled), the BOR bit is '1' on a Power-on Reset. After a Brownout Reset has occurred, the BOR bit will be cleared, and must be set by firmware to indicate the occurrence of the next Brown-out Reset. 2: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent Power-on Resets may be detected.
REGISTER 4-3:
RCON REGISTER
R/W-0 IPEN bit 7 U-0 -- U-0 -- R/W-1 RI R-1 TO R-1 PD R/W-0 POR R/W-0 BOR bit 0
bit 7
IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (16CXXX Compatibility mode) Unimplemented: Read as '0' RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed 0 = The RESET instruction was executed causing a device RESET (must be set in software after a Brown-out Reset occurs) TO: Watchdog Time-out Flag bit 1 = After power-up, CLRWDT instruction, or SLEEP instruction 0 = A WDT time-out occurred PD: Power-down Detection Flag bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction POR: Power-on Reset Status bit 1 = A Power-on Reset has not occurred 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) BOR: Brown-out Reset Status bit 1 = A Brown-out Reset has not occurred 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6-5 bit 4
bit 3
bit 2
bit 1
bit 0
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NOTES:
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5.0 FLASH PROGRAM MEMORY
5.1 Table Reads and Table Writes
The FLASH Program Memory is readable, writable, and erasable during normal operation over the entire VDD range. A read from program memory is executed on one byte at a time. A write to program memory is executed on blocks of 8 bytes at a time. Program memory is erased in blocks of 64 bytes at a time. A bulk erase operation may not be issued from user code. Writing or erasing program memory will cease instruction fetches until the operation is complete. The program memory cannot be accessed during the write or erase, therefore, code cannot execute. An internal programming timer terminates program memory writes and erases. A value written to program memory does not need to be a valid instruction. Executing a program memory location that forms an invalid instruction results in a NOP. In order to read and write program memory, there are two operations that allow the processor to move bytes between the program memory space and the data RAM: * Table Read (TBLRD) * Table Write (TBLWT) The program memory space is 16-bits wide, while the data RAM space is 8-bits wide. Table Reads and Table Writes move data between these two memory spaces through an 8-bit register (TABLAT). Table Read operations retrieve data from program memory and places it into the data RAM space. Figure 5-1 shows the operation of a Table Read with program memory and data RAM. Table Write operations store data from the data memory space into holding registers in program memory. The procedure to write the contents of the holding registers into program memory is detailed in Section 5.5, '"Writing to FLASH Program Memory". Figure 5-2 shows the operation of a Table Write with program memory and data RAM. Table operations work with byte entities. A table block containing data, rather than program instructions, is not required to be word aligned. Therefore, a table block can start and end at any byte address. If a Table Write is being used to write executable code into program memory, program instructions will need to be word aligned.
FIGURE 5-1:
TABLE READ OPERATION
Instruction: TBLRD*
Table Pointer(1) TBLPTRU TBLPTRH TBLPTRL
Program Memory Table Latch (8-bit) TABLAT
Program Memory (TBLPTR)
Note 1: Table Pointer points to a byte in program memory.
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FIGURE 5-2: TABLE WRITE OPERATION
Instruction: TBLWT*
Program Memory Holding Registers Table Pointer(1) TBLPTRU TBLPTRH TBLPTRL Table Latch (8-bit) TABLAT
Program Memory (TBLPTR)
Note 1: Table Pointer actually points to one of eight holding registers, the address of which is determined by TBLPTRL<2:0>. The process for physically writing data to the Program Memory Array is discussed in Section 5.5.
5.2
Control Registers
Several control registers are used in conjunction with the TBLRD and TBLWT instructions. These include the: * * * * EECON1 register EECON2 register TABLAT register TBLPTR registers
The FREE bit, when set, will allow a program memory erase operation. When the FREE bit is set, the erase operation is initiated on the next WR command. When FREE is clear, only writes are enabled. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set when a write operation is interrupted by a MCLR Reset or a WDT Time-out Reset during normal operation. In these situations, the user can check the WRERR bit and rewrite the location. It is necessary to reload the data and address registers (EEDATA and EEADR), due to RESET values of zero. Control bit WR initiates write operations. This bit cannot be cleared, only set, in software. It is cleared in hardware at the completion of the write operation. The inability to clear the WR bit in software prevents the accidental or premature termination of a write operation. Note: Interrupt flag bit EEIF, in the PIR2 register, is set when the write is complete. It must be cleared in software.
5.2.1
EECON1 AND EECON2 REGISTERS
EECON1 is the control register for memory accesses. EECON2 is not a physical register. Reading EECON2 will read all '0's. The EECON2 register is used exclusively in the memory write and erase sequences. Control bit EEPGD determines if the access will be a program or data EEPROM memory access. When clear, any subsequent operations will operate on the data EEPROM memory. When set, any subsequent operations will operate on the program memory. Control bit CFGS determines if the access will be to the configuration registers or to program memory/data EEPROM memory. When set, subsequent operations will operate on configuration registers, regardless of EEPGD (see "Special Features of the CPU", Section 19.0). When clear, memory selection access is determined by EEPGD.
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REGISTER 5-1: EECON1 REGISTER (ADDRESS FA6h)
R/W-x EEPGD bit 7 bit 7 EEPGD: FLASH Program or Data EEPROM Memory Select bit 1 = Access FLASH Program memory 0 = Access Data EEPROM memory CFGS: FLASH Program/Data EE or Configuration Select bit 1 = Access Configuration registers 0 = Access FLASH Program or Data EEPROM memory Unimplemented: Read as '0' FREE: FLASH Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only WRERR: FLASH Program/Data EE Error Flag bit 1 = A write operation is prematurely terminated (any RESET during self-timed programming in normal operation) 0 = The write operation completed Note: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error condition. R/W-x CFGS U-0 -- R/W-0 FREE R/W-x WRERR R/W-0 WREN R/S-0 WR R/S-0 RD bit 0
bit 6
bit 5 bit 4
bit 3
bit 2
WREN: FLASH Program/Data EE Write Enable bit 1 = Allows write cycles 0 = Inhibits write to the EEPROM WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle. (The operation is self timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete RD: Read Control bit 1 = Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1.) 0 = Does not initiate an EEPROM read Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 1
bit 0
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5.2.2 TABLAT - TABLE LATCH REGISTER 5.2.4 TABLE POINTER BOUNDARIES
The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The Table Latch is used to hold 8-bit data during data transfers between program memory and data RAM. TBLPTR is used in reads, writes, and erases of the FLASH program memory. When a TBLRD is executed, all 22 bits of the Table Pointer determine which byte is read from program memory into TABLAT. When a TBLWT is executed, the three LSbs of the Table Pointer (TBLPTR<2:0>) determine which of the eight program memory holding registers is written to. When the timed write to program memory (long write) begins, the 19 MSbs of the Table Pointer, TBLPTR (TBLPTR<21:3>), will determine which program memory block of 8 bytes is written to. For more detail, see Section 5.5 ("Writing to FLASH Program Memory"). When an erase of program memory is executed, the 16 MSbs of the Table Pointer (TBLPTR<21:6>) point to the 64-byte block that will be erased. The Least Significant bits (TBLPTR<5:0>) are ignored. Figure 5-3 describes the relevant boundaries of TBLPTR based on FLASH program memory operations.
5.2.3
TBLPTR - TABLE POINTER REGISTER
The Table Pointer (TBLPTR) addresses a byte within the program memory. The TBLPTR is comprised of three SFR registers: Table Pointer Upper Byte, Table Pointer High Byte and Table Pointer Low Byte (TBLPTRU:TBLPTRH:TBLPTRL). These three registers join to form a 22-bit wide pointer. The low order 21 bits allow the device to address up to 2 Mbytes of program memory space. The 22nd bit allows access to the Device ID, the User ID and the Configuration bits. The table pointer, TBLPTR, is used by the TBLRD and TBLWT instructions. These instructions can update the TBLPTR in one of four ways based on the table operation. These operations are shown in Table 5-1. These operations on the TBLPTR only affect the low order 21 bits.
TABLE 5-1:
Example TBLRD* TBLWT* TBLRD*+ TBLWT*+ TBLRD*TBLWT*TBLRD+* TBLWT+*
TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
Operation on Table Pointer TBLPTR is not modified TBLPTR is incremented after the read/write TBLPTR is decremented after the read/write TBLPTR is incremented before the read/write
FIGURE 5-3:
21
TABLE POINTER BOUNDARIES BASED ON OPERATION
TBLPTRU 16 15 TBLPTRH 8 7 TBLPTRL 0
ERASE - TBLPTR<21:6> WRITE - TBLPTR<21:3> READ - TBLPTR<21:0>
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5.3 Reading the FLASH Program Memory
TBLPTR points to a byte address in program space. Executing TBLRD places the byte pointed to into TABLAT. In addition, TBLPTR can be modified automatically for the next Table Read operation. The internal program memory is typically organized by words. The Least Significant bit of the address selects between the high and low bytes of the word. Figure 5-4 shows the interface between the internal program memory and the TABLAT.
The TBLRD instruction is used to retrieve data from program memory and place into data RAM. Table Reads from program memory are performed one byte at a time.
FIGURE 5-4:
READS FROM FLASH PROGRAM MEMORY
Program Memory
(Even Byte Address)
(Odd Byte Address)
TBLPTR = xxxxx1
TBLPTR = xxxxx0
Instruction Register (IR)
FETCH
TBLRD
TABLAT Read Register
EXAMPLE 5-1:
MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF READ_WORD
READING A FLASH PROGRAM MEMORY WORD
CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; Load TBLPTR with the base ; address of the word
TBLRD*+ MOVF TABLAT, W MOVWF WORD_EVEN TBLRD*+ MOVF TABLAT, W MOVWF WORD_ODD
; read into TABLAT and increment ; get data ; read into TABLAT and increment ; get data
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5.4 Erasing FLASH Program memory
5.4.1
The minimum erase block is 32 words or 64 bytes. Only through the use of an external programmer, or through ICSP control can larger blocks of program memory be bulk erased. Word erase in the FLASH array is not supported. When initiating an erase sequence from the microcontroller itself, a block of 64 bytes of program memory is erased. The Most Significant 16 bits of the TBLPTR<21:6> point to the block being erased. TBLPTR<5:0> are ignored. The EECON1 register commands the erase operation. The EEPGD bit must be set to point to the FLASH program memory. The WREN bit must be set to enable write operations. The FREE bit is set to select an erase operation. For protection, the write initiate sequence for EECON2 must be used. A long write is necessary for erasing the internal FLASH. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer.
FLASH PROGRAM MEMORY ERASE SEQUENCE
The sequence of events for erasing a block of internal program memory location is: 1. 2. Load table pointer with address of row being erased. Set EEPGD bit to point to program memory, clear CFGS bit to access program memory, set WREN bit to enable writes, and set FREE bit to enable the erase. Disable interrupts. Write 55h to EECON2. Write AAh to EECON2. Set the WR bit. This will begin the row erase cycle. The CPU will stall for duration of the erase (about 2 ms using internal timer). Re-enable interrupts.
3. 4. 5. 6. 7. 8.
EXAMPLE 5-2:
ERASING A FLASH PROGRAM MEMORY ROW
MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL EECON1,EEPGD EECON1,CFGS EECON1,WREN EECON1,FREE INTCON,GIE 55h EECON2 AAh EECON2 EECON1,WR INTCON,GIE ; load TBLPTR with the base ; address of the memory block
ERASE_ROW BSF BCF BSF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF ; ; ; ; ; point to FLASH program memory access FLASH program memory enable write to memory enable Row Erase operation disable interrupts
Required Sequence
; write 55h ; write AAh ; start erase (CPU stall) ; re-enable interrupts
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5.5 Writing to FLASH Program Memory
operations will essentially be short writes, because only the holding registers are written. At the end of updating 8 registers, the EECON1 register must be written to, to start the programming operation with a long write. The long write is necessary for programming the internal FLASH. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. The EEPROM on-chip timer controls the write time. The write/erase voltages are generated by an on-chip charge pump rated to operate over the voltage range of the device for byte or word operations.
The minimum programming block is 4 words or 8 bytes. Word or byte programming is not supported. Table Writes are used internally to load the holding registers needed to program the FLASH memory. There are 8 holding registers used by the Table Writes for programming. Since the Table Latch (TABLAT) is only a single byte, the TBLWT instruction has to be executed 8 times for each programming operation. All of the Table Write
FIGURE 5-5:
TABLE WRITES TO FLASH PROGRAM MEMORY
TABLAT Write Register
8
TBLPTR = xxxxx0 TBLPTR = xxxxx1
8
TBLPTR = xxxxx2
8
TBLPTR = xxxxx7
8
Holding Register
Holding Register
Holding Register
Holding Register
Program Memory
5.5.1
FLASH PROGRAM MEMORY WRITE SEQUENCE
The sequence of events for programming an internal program memory location should be: 1. 2. 3. 4. 5. 6. 7. Read 64 bytes into RAM. Update data values in RAM as necessary. Load Table Pointer with address being erased. Do the row erase procedure. Load Table Pointer with address of first byte being written. Write the first 8 bytes into the holding registers with auto-increment (TBLWT*+ or TBLWT+*). Set EEPGD bit to point to program memory, clear the CFGS bit to access program memory, and set WREN to enable byte writes. Disable interrupts. Write 55h to EECON2.
10. Write AAh to EECON2. 11. Set the WR bit. This will begin the write cycle. 12. The CPU will stall for duration of the write (about 2 ms using internal timer). 13. Re-enable interrupts. 14. Repeat steps 6-14 seven times, to write 64 bytes. 15. Verify the memory (Table Read). This procedure will require about 18 ms to update one row of 64 bytes of memory. An example of the required code is given in Example 5-3. Note: Before setting the WR bit, the table pointer address needs to be within the intended address range of the 8 bytes in the holding registers.
8. 9.
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EXAMPLE 5-3:
MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF READ_BLOCK TBLRD*+ MOVF MOVWF DECFSZ BRA MODIFY_WORD MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF ERASE_BLOCK MOVLW CODE_ADDR_UPPER MOVWF TBLPTRU MOVLW CODE_ADDR_HIGH MOVWF TBLPTRH MOVLW CODE_ADDR_LOW MOVWF TBLPTRL BSF EECON1,EEPGD BCF EECON1,CFGS BSF EECON1,WREN BSF EECON1,FREE BCF INTCON,GIE MOVLW 55h MOVWF EECON2 MOVLW AAh MOVWF EECON2 BSF EECON1,WR BSF INTCON,GIE TBLRD*WRITE_BUFFER_BACK MOVLW 8 MOVWF COUNTER_HI MOVLW BUFFER_ADDR_HIGH MOVWF FSR0H MOVLW BUFFER_ADDR_LOW MOVWF FSR0L PROGRAM_LOOP MOVLW 8 MOVWF COUNTER WRITE_WORD_TO_HREGS MOVF POSTINC0, W MOVWF TABLAT TBLWT+* DECFSZ COUNTER BRA WRITE_WORD_TO_HREGS ; load TBLPTR with the base ; address of the memory block DATA_ADDR_HIGH FSR0H DATA_ADDR_LOW FSR0L NEW_DATA_LOW POSTINC0 NEW_DATA_HIGH INDF0 ; point to buffer TABLAT, W POSTINC0 COUNTER READ_BLOCK ; ; ; ; ; read into TABLAT, and inc get data store data done? repeat
WRITING TO FLASH PROGRAM MEMORY
D'64 COUNTER BUFFER_ADDR_HIGH FSR0H BUFFER_ADDR_LOW FSR0L CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; number of bytes in erase block ; point to buffer
; Load TBLPTR with the base ; address of the memory block
; update buffer word
; ; ; ; ;
point to FLASH program memory access FLASH program memory enable write to memory enable Row Erase operation disable interrupts
; write 55h ; ; ; ; write AAh start erase (CPU stall) re-enable interrupts dummy read decrement
; number of write buffer groups of 8 bytes ; point to buffer
; number of bytes in holding register
; ; ; ; ;
get low byte of buffer data present data to table latch write data, perform a short write to internal TBLWT holding register. loop until buffers are full
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EXAMPLE 5-3:
PROGRAM_MEMORY BSF BCF BSF BCF MOVLW Required MOVWF Sequence MOVLW MOVWF BSF BSF DECFSZ BRA BCF
WRITING TO FLASH PROGRAM MEMORY (CONTINUED)
EECON1,EEPGD EECON1,CFGS EECON1,WREN INTCON,GIE 55h EECON2 AAh EECON2 EECON1,WR INTCON,GIE COUNTER_HI PROGRAM_LOOP EECON1,WREN ; ; ; ; point to FLASH program memory access FLASH program memory enable write to memory disable interrupts
; write 55h ; ; ; ; write AAh start program (CPU stall) re-enable interrupts loop until done
; disable write to memory
5.5.2
WRITE VERIFY
5.5.4
Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit.
PROTECTION AGAINST SPURIOUS WRITES
To protect against spurious writes to FLASH program memory, the write initiate sequence must also be followed. See "Special Features of the CPU" (Section 19.0) for more detail.
5.5.3
UNEXPECTED TERMINATION OF WRITE OPERATION
5.6
FLASH Program Operation During Code Protection
If a write is terminated by an unplanned event, such as loss of power or an unexpected RESET, the memory location just programmed should be verified and reprogrammed if needed.The WRERR bit is set when a write operation is interrupted by a MCLR Reset, or a WDT Time-out Reset during normal operation. In these situations, users can check the WRERR bit and rewrite the location.
See "Special Features of the CPU" (Section 19.0) for details on code protection of FLASH program memory.
TABLE 5-2:
Address FF8h FF7h FF6h FF5h FF2h FA7h FA6h FA2h FA1h FA0h Legend: Name
REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY
Bit 7 -- Bit 6 -- Bit 5 bit21 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on All Other RESETS
TBLPTRU
Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
--00 0000 --00 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) TBLPTRL Program Memory Table Pointer High Byte (TBLPTR<7:0>) TABLAT INTCON EECON2 EECON1 IPR2 PIR2 PIE2 Program Memory Table Latch GIE/ GIEH EEPGD -- -- -- PEIE/ GIEL CFGS -- -- -- TMR0IE INTE RBIE TMR0IF INTF RBIF
0000 000x 0000 000u
EEPROM Control Register2 (not a physical register) -- -- -- -- FREE EEIP EEIF EEIE WRERR BCLIP BCLIF BCLIE WREN LVDIP LVDIF LVDIE WR TMR3IP TMR3IF TMR3IE RD CCP2IP CCP2IF CCP2IE
--
--
xx-0 x000 uu-0 u000 ---1 1111 ---1 1111 ---0 0000 ---0 0000 ---0 0000 ---0 0000
x = unknown, u = unchanged, r = reserved, - = unimplemented read as '0'. Shaded cells are not used during FLASH/EEPROM access.
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6.0 DATA EEPROM MEMORY
6.1 EEADR
The Data EEPROM is readable and writable during normal operation over the entire VDD range. The data memory is not directly mapped in the register file space. Instead, it is indirectly addressed through the Special Function Registers (SFR). There are four SFRs used to read and write the program and data EEPROM memory. These registers are: * * * * EECON1 EECON2 EEDATA EEADR The address register can address up to a maximum of 256 bytes of data EEPROM.
6.2
EECON1 and EECON2 Registers
EECON1 is the control register for EEPROM memory accesses. EECON2 is not a physical register. Reading EECON2 will read all '0's. The EECON2 register is used exclusively in the EEPROM write sequence. Control bits RD and WR initiate read and write operations, respectively. These bits cannot be cleared, only set, in software. They are cleared in hardware at the completion of the read or write operation. The inability to clear the WR bit in software prevents the accidental or premature termination of a write operation. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set when a write operation is interrupted by a MCLR Reset, or a WDT Time-out Reset during normal operation. In these situations, the user can check the WRERR bit and rewrite the location. It is necessary to reload the data and address registers (EEDATA and EEADR), due to the RESET condition forcing the contents of the registers to zero.
The EEPROM data memory allows byte read and write. When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and EEADR holds the address of the EEPROM location being accessed. These devices have 256 bytes of data EEPROM with an address range from 0h to FFh. The EEPROM data memory is rated for high erase/ write cycles. A byte write automatically erases the location and writes the new data (erase-before-write). The write time is controlled by an on-chip timer. The write time will vary with voltage and temperature, as well as from chip to chip. Please refer to parameter D122 (Electrical Characteristics, Section 22.0) for exact limits.
Note:
Interrupt flag bit, EEIF in the PIR2 register, is set when write is complete. It must be cleared in software.
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REGISTER 6-1: EECON1 REGISTER (ADDRESS FA6h)
R/W-x EEPGD bit 7 bit 7 EEPGD: FLASH Program or Data EEPROM Memory Select bit 1 = Access FLASH Program memory 0 = Access Data EEPROM memory CFGS: FLASH Program/Data EE or Configuration Select bit 1 = Access Configuration or Calibration registers 0 = Access FLASH Program or Data EEPROM memory Unimplemented: Read as '0' FREE: FLASH Row Erase Enable bit 1 = Erase the program memory row addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only WRERR: FLASH Program/Data EE Error Flag bit 1 = A write operation is prematurely terminated (any MCLR or any WDT Reset during self-timed programming in normal operation) 0 = The write operation completed Note: When a WRERR occurs, the EEPGD or FREE bits are not cleared. This allows tracing of the error condition. R/W-x CFGS U-0 -- R/W-0 FREE R/W-x WRERR R/W-0 WREN R/S-0 WR R/S-0 RD bit 0
bit 6
bit 5 bit 4
bit 3
bit 2
WREN: FLASH Program/Data EE Write Enable bit 1 = Allows write cycles 0 = Inhibits write to the EEPROM WR: Write Control bit 1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle. (The operation is self-timed and the bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete RD: Read Control bit 1 = Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software. RD bit cannot be set when EEPGD = 1.) 0 = Does not initiate an EEPROM read Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 1
bit 0
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PIC18FXX2
6.3 Reading the Data EEPROM Memory
(EECON1<6>), and then set control bit RD (EECON1<0>). The data is available for the very next instruction cycle; therefore, the EEDATA register can be read by the next instruction. EEDATA will hold this value until another read operation, or until it is written to by the user (during a write operation).
To read a data memory location, the user must write the address to the EEADR register, clear the EEPGD control bit (EECON1<7>), clear the CFGS control bit
EXAMPLE 6-1:
MOVLW MOVWF BCF BCF BSF MOVF
DATA EEPROM READ
DATA_EE_ADDR EEADR EECON1, EEPGD EECON1, CFGS EECON1, RD EEDATA, W ; ; ; ; ; ; Data Memory Address to read Point to DATA memory Access program FLASH or Data EEPROM memory EEPROM Read W = EEDATA
6.4
Writing to the Data EEPROM Memory
cution (i.e., runaway programs). The WREN bit should be kept clear at all times, except when updating the EEPROM. The WREN bit is not cleared by hardware. After a write sequence has been initiated, EECON1, EEADR and EDATA cannot be modified. The WR bit will be inhibited from being set unless the WREN bit is set. The WREN bit must be set on a previous instruction. Both WR and WREN cannot be set with the same instruction. At the completion of the write cycle, the WR bit is cleared in hardware and the EEPROM Write Complete Interrupt Flag bit (EEIF) is set. The user may either enable this interrupt, or poll this bit. EEIF must be cleared by software.
To write an EEPROM data location, the address must first be written to the EEADR register and the data written to the EEDATA register. Then the sequence in Example 6-2 must be followed to initiate the write cycle. The write will not initiate if the above sequence is not exactly followed (write 55h to EECON2, write AAh to EECON2, then set WR bit) for each byte. It is strongly recommended that interrupts be disabled during this code segment. Additionally, the WREN bit in EECON1 must be set to enable writes. This mechanism prevents accidental writes to data EEPROM due to unexpected code exe-
EXAMPLE 6-2:
DATA EEPROM WRITE
MOVLW MOVWF MOVLW MOVWF BCF BCF BSF DATA_EE_ADDR EEADR DATA_EE_DATA EEDATA EECON1, EEPGD EECON1, CFGS EECON1, WREN ; ; ; ; ; ; ; Data Memory Address to read Data Memory Value to write Point to DATA memory Access program FLASH or Data EEPROM memory Enable writes
Required Sequence
BCF MOVLW MOVWF MOVLW MOVWF BSF BSF
INTCON, GIE 55h EECON2 AAh EECON2 EECON1, WR INTCON, GIE
; ; ; ; ; ; ;
Disable interrupts Write 55h Write AAh Set WR bit to begin write Enable interrupts
. . . BCF
; user code execution
EECON1, WREN
; Disable writes on write complete (EEIF set)
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PIC18FXX2
6.5 Write Verify 6.7 Operation During Code Protect
Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. Data EEPROM memory has its own code protect mechanism. External Read and Write operations are disabled if either of these mechanisms are enabled. The microcontroller itself can both read and write to the internal Data EEPROM, regardless of the state of the code protect configuration bit. Refer to "Special Features of the CPU" (Section 19.0) for additional information.
6.6
Protection Against Spurious Write
There are conditions when the device may not want to write to the data EEPROM memory. To protect against spurious EEPROM writes, various mechanisms have been built-in. On power-up, the WREN bit is cleared. Also, the Power-up Timer (72 ms duration) prevents EEPROM write. The write initiate sequence and the WREN bit together help prevent an accidental write during brown-out, power glitch, or software malfunction.
6.8
Using the Data EEPROM
The data EEPROM is a high endurance, byte addressable array that has been optimized for the storage of frequently changing information (e.g., program variables or other data that are updated often). Frequently changing values will typically be updated more often than specification D124. If this is not the case, an array refresh must be performed. For this reason, variables that change infrequently (such as constants, IDs, calibration, etc.) should be stored in FLASH program memory. A simple data EEPROM refresh routine is shown in Example 6-3. Note: If data EEPROM is only used to store constants and/or data that changes rarely, an array refresh is likely not required. See specification D124.
EXAMPLE 6-3:
clrf bcf bcf bcf bsf Loop bsf movlw movwf movlw movwf bsf btfsc bra incfsz bra bcf bsf
DATA EEPROM REFRESH ROUTINE
EEADR EECON1,CFGS EECON1,EEPGD INTCON,GIE EECON1,WREN EECON1,RD 55h EECON2 AAh EECON2 EECON1,WR EECON1,WR $-2 EEADR,F Loop EECON1,WREN INTCON,GIE ; ; ; ; ; ; ; ; ; ; ; ; ; Start at address 0 Set for memory Set for Data EEPROM Disable interrupts Enable writes Loop to refresh array Read current address Write 55h Write AAh Set WR bit to begin write Wait for write to complete
; Increment address ; Not zero, do it again ; Disable writes ; Enable interrupts
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PIC18FXX2
TABLE 6-1:
Address FF2h FA9h FA8h FA7h FA6h FA2h FA1h FA0h Legend:
REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY
Bit 7 GIE/ GIEH Bit 6 PEIE/ GIEL Bit 5 T0IE Bit 4 INTE Bit 3 RBIE Bit 2 T0IF Bit 1 INTF Bit 0 RBIF Value on: POR, BOR 0000 000x 0000 0000 0000 0000 -- WR RD xx-0 x000
TMR3IP CCP2IP ---1 1111
Name INTCON EEADR EEDATA EECON1 IPR2 PIR2 PIE2
Value on All Other RESETS 0000 000u 0000 0000 0000 0000 -- uu-0 u000 ---1 1111 ---0 0000 ---0 0000
EEPROM Address Register EEPROM Data Register EEPGD -- -- -- CFGS -- -- -- -- -- -- -- FREE
EEIP
EECON2 EEPROM Control Register2 (not a physical register) WRERR
BCLIP
WREN
LVDIP
EEIF EEIE
BCLIF BCLIE
LVDIF LVDIE
TMR3IF CCP2IF ---0 0000 TMR3IE CCP2IE ---0 0000
x = unknown, u = unchanged, r = reserved, - = unimplemented, read as '0'. Shaded cells are not used during FLASH/EEPROM access.
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PIC18FXX2
NOTES:
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PIC18FXX2
7.0
7.1
8 X 8 HARDWARE MULTIPLIER
Introduction
Making the 8 x 8 multiplier execute in a single cycle gives the following advantages: * Higher computational throughput * Reduces code size requirements for multiply algorithms The performance increase allows the device to be used in applications previously reserved for Digital Signal Processors. Table 7-1 shows a performance comparison between enhanced devices using the single cycle hardware multiply, and performing the same function without the hardware multiply.
An 8 x 8 hardware multiplier is included in the ALU of the PIC18FXX2 devices. By making the multiply a hardware operation, it completes in a single instruction cycle. This is an unsigned multiply that gives a 16-bit result. The result is stored into the 16-bit product register pair (PRODH:PRODL). The multiplier does not affect any flags in the ALUSTA register.
TABLE 7-1:
Routine
PERFORMANCE COMPARISON
Multiply Method Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Program Memory (Words) 13 1 33 6 21 24 52 36 Cycles (Max) 69 1 91 6 242 24 254 36 Time @ 40 MHz 6.9 s 100 ns 9.1 s 600 ns 24.2 s 2.4 s 25.4 s 3.6 s @ 10 MHz 27.6 s 400 ns 36.4 s 2.4 s 96.8 s 9.6 s 102.6 s 14.4 s @ 4 MHz 69 s 1 s 91 s 6 s 242 s 24 s 254 s 36 s
8 x 8 unsigned 8 x 8 signed 16 x 16 unsigned 16 x 16 signed
7.2
Operation
EXAMPLE 7-2:
MOVF MULWF BTFSC SUBWF MOVF BTFSC SUBWF ARG1, ARG2 W
Example 7-1 shows the sequence to do an 8 x 8 unsigned multiply. Only one instruction is required when one argument of the multiply is already loaded in the WREG register. Example 7-2 shows the sequence to do an 8 x 8 signed multiply. To account for the sign bits of the arguments, each argument's Most Significant bit (MSb) is tested and the appropriate subtractions are done.
8 x 8 SIGNED MULTIPLY ROUTINE
; ; ; ; ; ARG1 * ARG2 -> PRODH:PRODL Test Sign Bit PRODH = PRODH - ARG1
ARG2, SB PRODH, F ARG2, W ARG1, SB PRODH, F
EXAMPLE 7-1:
MOVF MULWF ARG1, W ARG2
8 x 8 UNSIGNED MULTIPLY ROUTINE
; ; ARG1 * ARG2 -> ; PRODH:PRODL
; Test Sign Bit ; PRODH = PRODH ; - ARG2
Example 7-3 shows the sequence to do a 16 x 16 unsigned multiply. Equation 7-1 shows the algorithm that is used. The 32-bit result is stored in four registers, RES3:RES0.
EQUATION 7-1:
16 x 16 UNSIGNED MULTIPLICATION ALGORITHM
ARG1H:ARG1L * ARG2H:ARG2L (ARG1H * ARG2H * 216) + (ARG1H * ARG2L * 28) + (ARG1L * ARG2H * 28) + (ARG1L * ARG2L)
RES3:RES0
= =
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PIC18FXX2
EXAMPLE 7-3:
MOVF MULWF MOVFF MOVFF ; MOVF MULWF MOVFF MOVFF ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ARG1H, W ARG2L PRODL, RES1, PRODH, RES2, WREG RES3, W F W F F ; ; ; ; ; ; ; ; ; ARG1H * ARG2L -> PRODH:PRODL Add cross products ARG1L, W ARG2H PRODL, RES1, PRODH, RES2, WREG RES3, W F W F F ; ; ; ; ; ; ; ; ARG1L * ARG2H -> PRODH:PRODL Add cross products ARG1H, W ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL PRODH, RES3 ; PRODL, RES2 ; ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ; MOVF MULWF MOVF ADDWF MOVF ADDWFC CLRF ADDWFC ; BTFSS BRA MOVF SUBWF MOVF SUBWFB ; SIGN_ARG1 BTFSS BRA MOVF SUBWF MOVF SUBWFB ; CONT_CODE : ARG1H, W ARG2L PRODL, RES1, PRODH, RES2, WREG RES3, W F W F F ; ; ; ; ; ; ; ; ; ARG1H * ARG2L -> PRODH:PRODL Add cross products ARG1L, W ARG2H PRODL, RES1, PRODH, RES2, WREG RES3, W F W F F ; ; ; ; ; ; ; ; ARG1L * ARG2H -> PRODH:PRODL Add cross products
16 x 16 UNSIGNED MULTIPLY ROUTINE
EXAMPLE 7-4:
MOVF MULWF MOVFF MOVFF ; MOVF MULWF MOVFF MOVFF
16 x 16 SIGNED MULTIPLY ROUTINE
; ARG1L * ARG2L -> ; PRODH:PRODL ; ;
ARG1L, W ARG2L
; ARG1L * ARG2L -> ; PRODH:PRODL PRODH, RES1 ; PRODL, RES0 ;
ARG1L, W ARG2L PRODH, RES1 PRODL, RES0 ARG1H, W ARG2H PRODH, RES3 PRODL, RES2
; ARG1H * ARG2H -> ; PRODH:PRODL ; ;
Example 7-4 shows the sequence to do a 16 x 16 signed multiply. Equation 7-2 shows the algorithm used. The 32-bit result is stored in four registers, RES3:RES0. To account for the sign bits of the arguments, each argument pairs Most Significant bit (MSb) is tested and the appropriate subtractions are done.
ARG2H, 7 SIGN_ARG1 ARG1L, W RES2 ARG1H, W RES3
; ARG2H:ARG2L neg? ; no, check ARG1 ; ; ;
EQUATION 7-2:
16 x 16 SIGNED MULTIPLICATION ALGORITHM
RES3:RES0 = ARG1H:ARG1L * ARG2H:ARG2L = (ARG1H * ARG2H * 216) + (ARG1H * ARG2L * 28) + (ARG1L * ARG2H * 28) + (ARG1L * ARG2L) + (-1 * ARG2H<7> * ARG1H:ARG1L * 216) + (-1 * ARG1H<7> * ARG2H:ARG2L * 216)
ARG1H, 7 CONT_CODE ARG2L, W RES2 ARG2H, W RES3
; ARG1H:ARG1L neg? ; no, done ; ; ;
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PIC18FXX2
8.0 INTERRUPTS
The PIC18FXX2 devices have multiple interrupt sources and an interrupt priority feature that allows each interrupt source to be assigned a high priority level or a low priority level. The high priority interrupt vector is at 000008h and the low priority interrupt vector is at 000018h. High priority interrupt events will override any low priority interrupts that may be in progress. There are ten registers which are used to control interrupt operation. These registers are: * * * * * * * RCON INTCON INTCON2 INTCON3 PIR1, PIR2 PIE1, PIE2 IPR1, IPR2 When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PICmicro(R) mid-range devices. In Compatibility mode, the interrupt priority bits for each source have no effect. INTCON<6> is the PEIE bit, which enables/disables all peripheral interrupt sources. INTCON<7> is the GIE bit, which enables/disables all interrupt sources. All interrupts branch to address 000008h in Compatibility mode. When an interrupt is responded to, the Global Interrupt Enable bit is cleared to disable further interrupts. If the IPEN bit is cleared, this is the GIE bit. If interrupt priority levels are used, this will be either the GIEH or GIEL bit. High priority interrupt sources can interrupt a low priority interrupt. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (000008h or 000018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bits must be cleared in software before re-enabling interrupts to avoid recursive interrupts. The "return from interrupt" instruction, RETFIE, exits the interrupt routine and sets the GIE bit (GIEH or GIEL if priority levels are used), which re-enables interrupts. For external interrupt events, such as the INT pins or the PORTB input change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding enable bit or the GIE bit. Note: Do not use the MOVFF instruction to modify any of the Interrupt control registers while any interrupt is enabled. Doing so may cause erratic microcontroller behavior.
It is recommended that the Microchip header files supplied with MPLAB(R) IDE be used for the symbolic bit names in these registers. This allows the assembler/ compiler to automatically take care of the placement of these bits within the specified register. Each interrupt source, except INT0, has three bits to control its operation. The functions of these bits are: * Flag bit to indicate that an interrupt event occurred * Enable bit that allows program execution to branch to the interrupt vector address when the flag bit is set * Priority bit to select high priority or low priority The interrupt priority feature is enabled by setting the IPEN bit (RCON<7>). When interrupt priority is enabled, there are two bits which enable interrupts globally. Setting the GIEH bit (INTCON<7>) enables all interrupts that have the priority bit set. Setting the GIEL bit (INTCON<6>) enables all interrupts that have the priority bit cleared. When the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address 000008h or 000018h, depending on the priority level. Individual interrupts can be disabled through their corresponding enable bits.
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PIC18FXX2
FIGURE 8-1: INTERRUPT LOGIC
TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP INT0IF INT0IE INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP
Wake-up if in SLEEP mode
Peripheral Interrupt Flag bit Peripheral Interrupt Enable bit Peripheral Interrupt Priority bit TMR1IF TMR1IE TMR1IP XXXXIF XXXXIE XXXXIP Additional Peripheral Interrupts High Priority Interrupt Generation Low Priority Interrupt Generation
Interrupt to CPU Vector to location 0008h
GIEH/GIE IPE IPEN GIEL/PEIE IPEN
Peripheral Interrupt Flag bit Peripheral Interrupt Enable bit Peripheral Interrupt Priority bit TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP INT1IF INT1IE INT1IP Additional Peripheral Interrupts INT2IF INT2IE INT2IP Interrupt to CPU Vector to Location 0018h
TMR1IF TMR1IE TMR1IP XXXXIF XXXXIE XXXXIP
GIEL/PEIE GIE/GIEH
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PIC18FXX2
8.1 INTCON Registers
Note: The INTCON Registers are readable and writable registers, which contain various enable, priority and flag bits. Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.
REGISTER 8-1:
INTCON REGISTER
R/W-0 GIE/GIEH bit 7 R/W-0 PEIE/GIEL R/W-0 TMR0IE R/W-0 INT0IE R/W-0 RBIE R/W-0 TMR0IF R/W-0 INT0IF R/W-x RBIF bit 0
bit 7
GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts When IPEN = 1: 1 = Enables all high priority interrupts 0 = Disables all interrupts PEIE/GIEL: Peripheral Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts When IPEN = 1: 1 = Enables all low priority peripheral interrupts 0 = Disables all low priority peripheral interrupts TMR0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 overflow interrupt 0 = Disables the TMR0 overflow interrupt INT0IE: INT0 External Interrupt Enable bit 1 = Enables the INT0 external interrupt 0 = Disables the INT0 external interrupt RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared in software) 0 = The INT0 external interrupt did not occur RBIF: RB Port Change Interrupt Flag bit 1 = At least one of the RB7:RB4 pins changed state (must be cleared in software) 0 = None of the RB7:RB4 pins have changed state Note: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and allow the bit to be cleared.
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
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PIC18FXX2
REGISTER 8-2: INTCON2 REGISTER
R/W-1 RBPU bit 7 bit 7 RBPU: PORTB Pull-up Enable bit 1 = All PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values INTEDG0:External Interrupt0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge INTEDG1: External Interrupt1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge INTEDG2: External Interrupt2 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge Unimplemented: Read as '0' TMR0IP: TMR0 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority Unimplemented: Read as '0' RBIP: RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-1 INTEDG0 R/W-1 INTEDG1 R/W-1 INTEDG2 U-0 -- R/W-1 TMR0IP U-0 -- R/W-1 RBIP bit 0
bit 6
bit 5
bit 4
bit 3 bit 2
bit 1 bit 0
Note:
Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.
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PIC18FXX2
REGISTER 8-3: INTCON3 REGISTER
R/W-1 INT2IP bit 7 bit 7 INT2IP: INT2 External Interrupt Priority bit 1 = High priority 0 = Low priority INT1IP: INT1 External Interrupt Priority bit 1 = High priority 0 = Low priority Unimplemented: Read as '0' INT2IE: INT2 External Interrupt Enable bit 1 = Enables the INT2 external interrupt 0 = Disables the INT2 external interrupt INT1IE: INT1 External Interrupt Enable bit 1 = Enables the INT1 external interrupt 0 = Disables the INT1 external interrupt Unimplemented: Read as '0' INT2IF: INT2 External Interrupt Flag bit 1 = The INT2 external interrupt occurred (must be cleared in software) 0 = The INT2 external interrupt did not occur INT1IF: INT1 External Interrupt Flag bit 1 = The INT1 external interrupt occurred (must be cleared in software) 0 = The INT1 external interrupt did not occur Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-1 INT1IP U-0 -- R/W-0 INT2IE R/W-0 INT1IE U-0 -- R/W-0 INT2IF R/W-0 INT1IF bit 0
bit 6
bit 5 bit 4
bit 3
bit 2 bit 1
bit 0
Note:
Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling.
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PIC18FXX2
8.2 PIR Registers
The PIR registers contain the individual flag bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Flag Registers (PIR1, PIR2). Note 1: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt, and after servicing that interrupt.
REGISTER 8-4:
PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
R/W-0 PSPIF bit 7
(1)
R/W-0 ADIF
R-0 RCIF
R-0 TXIF
R/W-0 SSPIF
R/W-0 CCP1IF
R/W-0 TMR2IF
R/W-0 TMR1IF bit 0
bit 7
PSPIF(1): Parallel Slave Port Read/Write Interrupt Flag bit 1 = A read or a write operation has taken place (must be cleared in software) 0 = No read or write has occurred ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete RCIF: USART Receive Interrupt Flag bit 1 = The USART receive buffer, RCREG, is full (cleared when RCREG is read) 0 = The USART receive buffer is empty TXIF: USART Transmit Interrupt Flag bit (see Section 16.0 for details on TXIF functionality) 1 = The USART transmit buffer, TXREG, is empty (cleared when TXREG is written) 0 = The USART transmit buffer is full SSPIF: Master Synchronous Serial Port Interrupt Flag bit 1 = The transmission/reception is complete (must be cleared in software) 0 = Waiting to transmit/receive CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = MR1 register did not overflow Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear. Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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PIC18FXX2
REGISTER 8-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
U-0 -- bit 7 bit 7-5 bit 4 Unimplemented: Read as '0' EEIF: Data EEPROM/FLASH Write Operation Interrupt Flag bit 1 = The Write operation is complete (must be cleared in software) 0 = The Write operation is not complete, or has not been started BCLIF: Bus Collision Interrupt Flag bit 1 = A bus collision occurred (must be cleared in software) 0 = No bus collision occurred LVDIF: Low Voltage Detect Interrupt Flag bit 1 = A low voltage condition occurred (must be cleared in software) 0 = The device voltage is above the Low Voltage Detect trip point TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared in software) 0 = TMR3 register did not overflow CCP2IF: CCPx Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown U-0 -- U-0 -- R/W-0 EEIF R/W-0 BCLIF R/W-0 LVDIF R/W-0 TMR3IF R/W-0 CCP2IF bit 0
bit 3
bit 2
bit 1
bit 0
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PIC18FXX2
8.3 PIE Registers
The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Enable Registers (PIE1, PIE2). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts.
REGISTER 8-6:
PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
R/W-0 PSPIE(1) bit 7 R/W-0 ADIE R/W-0 RCIE R/W-0 TXIE R/W-0 SSPIE R/W-0 CCP1IE R/W-0 TMR2IE R/W-0 TMR1IE bit 0
bit 7
PSPIE(1): Parallel Slave Port Read/Write Interrupt Enable bit 1 = Enables the PSP read/write interrupt 0 = Disables the PSP read/write interrupt ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt RCIE: USART Receive Interrupt Enable bit 1 = Enables the USART receive interrupt 0 = Disables the USART receive interrupt TXIE: USART Transmit Interrupt Enable bit 1 = Enables the USART transmit interrupt 0 = Disables the USART transmit interrupt SSPIE: Master Synchronous Serial Port Interrupt Enable bit 1 = Enables the MSSP interrupt 0 = Disables the MSSP interrupt CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear. Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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2002 Microchip Technology Inc.
PIC18FXX2
REGISTER 8-7: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
U-0 -- bit 7 bit 7-5 bit 4 Unimplemented: Read as '0' EEIE: Data EEPROM/FLASH Write Operation Interrupt Enable bit 1 = Enabled 0 = Disabled BCLIE: Bus Collision Interrupt Enable bit 1 = Enabled 0 = Disabled LVDIE: Low Voltage Detect Interrupt Enable bit 1 = Enabled 0 = Disabled TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enables the TMR3 overflow interrupt 0 = Disables the TMR3 overflow interrupt CCP2IE: CCP2 Interrupt Enable bit 1 = Enables the CCP2 interrupt 0 = Disables the CCP2 interrupt Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown U-0 -- U-0 -- R/W-0 EEIE R/W-0 BCLIE R/W-0 LVDIE R/W-0 TMR3IE R/W-0 CCP2IE bit 0
bit 3
bit 2
bit 1
bit 0
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PIC18FXX2
8.4 IPR Registers
The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Priority Registers (IPR1, IPR2). The operation of the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set.
REGISTER 8-8:
IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
R/W-1 PSPIP(1) bit 7 R/W-1 ADIP R/W-1 RCIP R/W-1 TXIP R/W-1 SSPIP R/W-1 CCP1IP R/W-1 TMR2IP R/W-1 TMR1IP bit 0
bit 7
PSPIP(1): Parallel Slave Port Read/Write Interrupt Priority bit 1 = High priority 0 = Low priority ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority RCIP: USART Receive Interrupt Priority bit 1 = High priority 0 = Low priority TXIP: USART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority SSPIP: Master Synchronous Serial Port Interrupt Priority bit 1 = High priority 0 = Low priority CCP1IP: CCP1 Interrupt Priority bit 1 = High priority 0 = Low priority TMR2IP: TMR2 to PR2 Match Interrupt Priority bit 1 = High priority 0 = Low priority TMR1IP: TMR1 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit set. Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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PIC18FXX2
REGISTER 8-9: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
U-0 -- bit 7 bit 7-5 bit 4 Unimplemented: Read as '0' EEIP: Data EEPROM/FLASH Write Operation Interrupt Priority bit 1 = High priority 0 = Low priority BCLIP: Bus Collision Interrupt Priority bit 1 = High priority 0 = Low priority LVDIP: Low Voltage Detect Interrupt Priority bit 1 = High priority 0 = Low priority TMR3IP: TMR3 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority CCP2IP: CCP2 Interrupt Priority bit 1 = High priority 0 = Low priority Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown U-0 -- U-0 -- R/W-1 EEIP R/W-1 BCLIP R/W-1 LVDIP R/W-1 TMR3IP R/W-1 CCP2IP bit 0
bit 3
bit 2
bit 1
bit 0
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PIC18FXX2
8.5 RCON Register
The RCON register contains the bit which is used to enable prioritized interrupts (IPEN).
REGISTER 8-10:
RCON REGISTER
R/W-0 IPEN bit 7 U-0 -- U-0 -- R/W-1 RI R-1 TO R-1 PD R/W-0 POR R/W-0 BOR bit 0
bit 7
IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (16CXXX Compatibility mode) Unimplemented: Read as '0' RI: RESET Instruction Flag bit For details of bit operation, see Register 4-3 TO: Watchdog Time-out Flag bit For details of bit operation, see Register 4-3 PD: Power-down Detection Flag bit For details of bit operation, see Register 4-3 POR: Power-on Reset Status bit For details of bit operation, see Register 4-3 BOR: Brown-out Reset Status bit For details of bit operation, see Register 4-3 Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6-5 bit 4 bit 3 bit 2 bit 1 bit 0
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PIC18FXX2
8.6 INT0 Interrupt 8.7 TMR0 Interrupt
External interrupts on the RB0/INT0, RB1/INT1 and RB2/INT2 pins are edge triggered: either rising, if the corresponding INTEDGx bit is set in the INTCON2 register, or falling, if the INTEDGx bit is clear. When a valid edge appears on the RBx/INTx pin, the corresponding flag bit INTxF is set. This interrupt can be disabled by clearing the corresponding enable bit INTxE. Flag bit INTxF must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1 and INT2) can wake-up the processor from SLEEP, if bit INTxE was set prior to going into SLEEP. If the global interrupt enable bit GIE is set, the processor will branch to the interrupt vector following wake-up. Interrupt priority for INT1 and INT2 is determined by the value contained in the interrupt priority bits, INT1IP (INTCON3<6>) and INT2IP (INTCON3<7>). There is no priority bit associated with INT0. It is always a high priority interrupt source. In 8-bit mode (which is the default), an overflow (FFh 00h) in the TMR0 register will set flag bit TMR0IF. In 16-bit mode, an overflow (FFFFh 0000h) in the TMR0H:TMR0L registers will set flag bit TMR0IF. The interrupt can be enabled/disabled by setting/ clearing enable bit T0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit TMR0IP (INTCON2<2>). See Section 10.0 for further details on the Timer0 module.
8.8
PORTB Interrupt-on-Change
An input change on PORTB<7:4> sets flag bit RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit, RBIE (INTCON<3>). Interrupt priority for PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RBIP (INTCON2<0>).
8.9
Context Saving During Interrupts
During an interrupt, the return PC value is saved on the stack. Additionally, the WREG, STATUS and BSR registers are saved on the fast return stack. If a fast return from interrupt is not used (See Section 4.3), the user may need to save the WREG, STATUS and BSR registers in software. Depending on the user's application, other registers may also need to be saved. Equation 8-1 saves and restores the WREG, STATUS and BSR registers during an Interrupt Service Routine.
EXAMPLE 8-1:
MOVWF MOVFF MOVFF ; ; USER ; MOVFF MOVF MOVFF
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
; W_TEMP is in virtual bank ; STATUS_TEMP located anywhere ; BSR located anywhere
W_TEMP STATUS, STATUS_TEMP BSR, BSR_TEMP ISR CODE BSR_TEMP, BSR W_TEMP, W STATUS_TEMP,STATUS
; Restore BSR ; Restore WREG ; Restore STATUS
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PIC18FXX2
NOTES:
DS39564B-page 86
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PIC18FXX2
9.0 I/O PORTS
EXAMPLE 9-1:
CLRF PORTA ; ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTA
Initialize PORTA by clearing output data latches Alternate method to clear output data latches Configure A/D for digital inputs Value used to initialize data direction Set RA<3:0> as inputs RA<5:4> as outputs
Depending on the device selected, there are either five ports or three ports available. Some pins of the I/O ports are multiplexed with an alternate function from the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Each port has three registers for its operation. These registers are: * TRIS register (data direction register) * PORT register (reads the levels on the pins of the device) * LAT register (output latch) The data latch (LAT register) is useful for read-modifywrite operations on the value that the I/O pins are driving.
CLRF LATA
MOVLW 0x07 MOVWF ADCON1 MOVLW 0xCF
MOVWF TRISA
FIGURE 9-1:
BLOCK DIAGRAM OF RA3:RA0 AND RA5 PINS
9.1
PORTA, TRISA and LATA Registers
RD LATA Data Bus D Q VDD WR LATA or PORTA CK Q P
PORTA is a 7-bit wide, bi-directional port. The corresponding Data Direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). Reading the PORTA register reads the status of the pins, whereas writing to it will write to the port latch. The Data Latch register (LATA) is also memory mapped. Read-modify-write operations on the LATA register reads and writes the latched output value for PORTA. The RA4 pin is multiplexed with the Timer0 module clock input to become the RA4/T0CKI pin. The RA4/ T0CKI pin is a Schmitt Trigger input and an open drain output. All other RA port pins have TTL input levels and full CMOS output drivers. The other PORTA pins are multiplexed with analog inputs and the analog VREF+ and VREF- inputs. The operation of each pin is selected by clearing/setting the control bits in the ADCON1 register (A/D Control Register1). Note: On a Power-on Reset, RA5 and RA3:RA0 are configured as analog inputs and read as `0'. RA6 and RA4 are configured as digital inputs.
Data Latch D Q N I/O pin(1)
WR TRISA CK Q TRIS Latch
VSS Analog Input Mode
RD TRISA Q D
TTL Input Buffer
EN RD PORTA SS Input (RA5 only) To A/D Converter and LVD Modules
Note 1:
I/O pins have protection diodes to VDD and VSS.
The TRISA register controls the direction of the RA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs.
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PIC18FXX2
FIGURE 9-2: BLOCK DIAGRAM OF RA4/T0CKI PIN FIGURE 9-3:
ECRA6 or RCRA6 Enable RD LATA Data Bus WR LATA or PORTA D Q Q N VSS Schmitt Trigger Input Buffer WR TRISA RD TRISA Q D RD TRISA EN EN RD PORTA ECRA6 or RCRA6 Enable Q D EN TMR0 Clock Input RD PORTA Note 1: I/O pin has protection diode to VSS only. Note 1: I/O pins have protection diodes to VDD and VSS. TTL Input Buffer D Q VDD P Data Bus RD LATA
BLOCK DIAGRAM OF RA6 PIN
CK
I/O pin(1) WR LATA or PORTA
Data Latch D Q Q
CK
Q
Data Latch D Q N I/O pin(1)
WR TRISA
CK
TRIS Latch
CK
Q
VSS
TRIS Latch
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2002 Microchip Technology Inc.
PIC18FXX2
TABLE 9-1:
Name RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/SS/AN4/LVDIN OSC2/CLKO/RA6
PORTA FUNCTIONS
Bit# bit0 bit1 bit2 bit3 bit4 bit5 bit6 Buffer TTL TTL TTL TTL ST TTL TTL Input/output or analog input. Input/output or analog input. Input/output or analog input or VREF-. Input/output or analog input or VREF+. Input/output or external clock input for Timer0. Output is open drain type. Input/output or slave select input for synchronous serial port or analog input, or low voltage detect input. OSC2 or clock output or I/O pin. Function
Legend: TTL = TTL input, ST = Schmitt Trigger input
TABLE 9-2:
Name PORTA LATA TRISA ADCON1
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Bit 7 -- -- -- ADFM Bit 6 RA6 Bit 5 RA5 Bit 4 RA4 Bit 3 RA3 Bit 2 RA2 Bit 1 RA1 Bit 0 RA0 Value on POR, BOR
-x0x 0000 -xxx xxxx -111 1111
Value on All Other RESETS
-u0u 0000 -uuu uuuu -111 1111 00-- 0000
LATA Data Output Register PORTA Data Direction Register ADCS2 -- -- PCFG3 PCFG2 PCFG1 PCFG0
00-- 0000
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA.
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PIC18FXX2
9.2 PORTB, TRISB and LATB Registers
The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. RB3 can be configured by the configuration bit CCP2MX as the alternate peripheral pin for the CCP2 module (CCP2MX='0').
PORTB is an 8-bit wide, bi-directional port. The corresponding Data Direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATB) is also memory mapped. Read-modify-write operations on the LATB register reads and writes the latched output value for PORTB.
FIGURE 9-4:
RBPU(2)
BLOCK DIAGRAM OF RB7:RB4 PINS
VDD Weak P Pull-up Data Latch D CK TRIS Latch D Q CK TTL Input Buffer Q I/O pin(1)
EXAMPLE 9-2:
CLRF PORTB ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTB
Initialize PORTB by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RB<3:0> as inputs RB<5:4> as outputs RB<7:6> as inputs
Data Bus WR LATB or PORTB
CLRF
LATB
WR TRISB
MOVLW 0xCF
ST Buffer
MOVWF TRISB
RD TRISB
RD LATB Q RD PORTB Set RBIF
Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit RBPU (INTCON2<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. Note: On a Power-on Reset, these pins are configured as digital inputs.
Latch D EN Q1
Q From other RB7:RB4 pins RB7:RB5 in Serial Programming mode Note 1: 2:
D RD PORTB EN Q3
Four of the PORTB pins, RB7:RB4, have an interrupton-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB4 pin configured as an output is excluded from the interrupton-change comparison). The input pins (of RB7:RB4) are compared with the old value latched on the last read of PORTB. The "mismatch" outputs of RB7:RB4 are OR'ed together to generate the RB Port Change Interrupt with flag bit, RBIF (INTCON<0>). This interrupt can wake the device from SLEEP. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) Any read or write of PORTB (except with the MOVFF instruction). This will end the mismatch condition. Clear flag bit RBIF.
I/O pins have diode protection to VDD and VSS. To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>).
Note 1: While in Low Voltage ICSP mode, the RB5 pin can no longer be used as a general purpose I/O pin, and should be held low during normal operation to protect against inadvertent ICSP mode entry. 2: When using Low Voltage ICSP programming (LVP), the pull-up on RB5 becomes disabled. If TRISB bit 5 is cleared, thereby setting RB5 as an output, LATB bit 5 must also be cleared for proper operation.
b)
A mismatch condition will continue to set flag bit RBIF. Reading PORTB will end the mismatch condition and allow flag bit RBIF to be cleared.
DS39564B-page 90
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 9-5: BLOCK DIAGRAM OF RB2:RB0 PINS
VDD RBPU(2) Data Latch D Q I/O pin(1) CK TRIS Latch D Q WR TRIS CK Weak P Pull-up
Data Bus WR Port
TTL Input Buffer
RD TRIS Q RD Port RB0/INT Schmitt Trigger Buffer Note 1: 2: RD Port D EN
I/O pins have diode protection to VDD and VSS. To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>).
FIGURE 9-6:
BLOCK DIAGRAM OF RB3 PIN
VDD RBPU
(2)
CCP2MX CCP Output(3) 1 VDD P Enable(3) CCP Output Data Bus WR LATB or WR PORTB Data Latch D CK TRIS Latch D WR TRISB CK Q Q N VSS 0
Weak P Pull-up
I/O pin(1)
TTL Input Buffer
RD TRISB RD LATB Q RD PORTB D EN
RD PORTB CCP2 Input(3) Schmitt Trigger Buffer Note 1: 2: 3: CCP2MX = 0
I/O pin has diode protection to VDD and VSS. To enable weak pull-ups, set the appropriate DDR bit(s) and clear the RBPU bit (INTCON2<7>). The CCP2 input/output is multiplexed with RB3 if the CCP2MX bit is enabled (='0') in the configuration register.
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TABLE 9-3:
Name RB0/INT0 RB1/INT1 RB2/INT2 RB3/CCP2(3)
PORTB FUNCTIONS
Bit# bit0 bit1 bit2 bit3 Buffer TTL/ST(1) TTL/ST(1) TTL/ST(1) TTL/ST(4) Function Input/output pin or external interrupt input0. Internal software programmable weak pull-up. Input/output pin or external interrupt input1. Internal software programmable weak pull-up. Input/output pin or external interrupt input2. Internal software programmable weak pull-up. Input/output pin or Capture2 input/Compare2 output/PWM output when CCP2MX configuration bit is enabled. Internal software programmable weak pull-up. Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Low voltage ICSP enable pin. Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Serial programming clock. Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. Serial programming data.
RB4 RB5/PGM(5)
bit4 bit5
TTL TTL/ST(2)
RB6/PGC
bit6
TTL/ST(2)
RB7/PGD
bit7
TTL/ST(2)
Legend: TTL = TTL input, ST = Schmitt Trigger input Note 1: 2: 3: 4: 5: This buffer is a Schmitt Trigger input when configured as the external interrupt. This buffer is a Schmitt Trigger input when used in Serial Programming mode. A device configuration bit selects which I/O pin the CCP2 pin is multiplexed on. This buffer is a Schmitt Trigger input when configured as the CCP2 input. Low Voltage ICSP Programming (LVP) is enabled by default, which disables the RB5 I/O function. LVP must be disabled to enable RB5 as an I/O pin and allow maximum compatibility to the other 28-pin and 40-pin mid-range devices.
TABLE 9-4:
Name PORTB LATB TRISB INTCON INTCON2 INTCON3
SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Bit 7 RB7 Bit 6 RB6 Bit 5 RB5 Bit 4 RB4 Bit 3 RB3 Bit 2 RB2 Bit 1 RB1 Bit 0 RB0 Value on POR, BOR
xxxx xxxx xxxx xxxx 1111 1111
Value on All Other RESETS
uuuu uuuu uuuu uuuu 1111 1111 0000 000u 1111 -1-1 11-0 0-00
LATB Data Output Register PORTB Data Direction Register GIE/ GIEH RBPU INT2IP PEIE/ GIEL INTEDG0 INT1IP TMR0IE INTEDG1 -- INT0IE INTEDG2 INT2IE RBIE -- INT1IE TMR0IF TMR0IP -- INT0IF -- INT2IF RBIF RBIP INT1IF
0000 000x 1111 -1-1 11-0 0-00
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.
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PIC18FXX2
9.3 PORTC, TRISC and LATC Registers
The pin override value is not loaded into the TRIS register. This allows read-modify-write of the TRIS register, without concern due to peripheral overrides. RC1 is normally configured by configuration bit, CCP2MX, as the default peripheral pin of the CCP2 module (default/erased state, CCP2MX = '1').
PORTC is an 8-bit wide, bi-directional port. The corresponding Data Direction register is TRISC. Setting a TRISC bit (= 1) will make the corresponding PORTC pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATC) is also memory mapped. Read-modify-write operations on the LATC register reads and writes the latched output value for PORTC. PORTC is multiplexed with several peripheral functions (Table 9-5). PORTC pins have Schmitt Trigger input buffers. When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for the correct TRIS bit settings. Note: On a Power-on Reset, these pins are configured as digital inputs.
EXAMPLE 9-3:
CLRF PORTC ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTC
Initialize PORTC by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RC<3:0> as inputs RC<5:4> as outputs RC<7:6> as inputs
CLRF
LATC
MOVLW 0xCF
MOVWF TRISC
FIGURE 9-7:
PORTC BLOCK DIAGRAM (PERIPHERAL OUTPUT OVERRIDE)
Port/Peripheral Select(2) VDD Peripheral Data Out
RD LATC Data Bus WR LATC or WR PORTC Data Latch D CK Q Q
1 0
P I/O pin(1)
TRIS Latch D Q WR TRISC CK Q N Schmitt Trigger
RD TRISC Peripheral Output Enable(3) Q RD PORTC Peripheral Data In Note 1: 2: 3: I/O pins have diode protection to VDD and VSS. D EN
VSS
Port/Peripheral Select signal selects between port data (input) and peripheral output. Peripheral Output Enable is only active if peripheral select is active.
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PIC18FXX2
TABLE 9-5:
Name RC0/T1OSO/T1CKI RC1/T1OSI/CCP2
PORTC FUNCTIONS
Bit# bit0 bit1 Buffer Type ST ST Function Input/output port pin or Timer1 oscillator output/Timer1 clock input. Input/output port pin, Timer1 oscillator input, or Capture2 input/ Compare2 output/PWM output when CCP2MX configuration bit is set. Input/output port pin or Capture1 input/Compare1 output/PWM1 output. RC3 can also be the synchronous serial clock for both SPI and I2C modes. RC4 can also be the SPI Data In (SPI mode) or Data I/O (I2C mode). Input/output port pin or Synchronous Serial Port data output. Input/output port pin, Addressable USART Asynchronous Transmit, or Addressable USART Synchronous Clock. Input/output port pin, Addressable USART Asynchronous Receive, or Addressable USART Synchronous Data.
RC2/CCP1 RC3/SCK/SCL RC4/SDI/SDA RC5/SDO RC6/TX/CK RC7/RX/DT
bit2 bit3 bit4 bit5 bit6 bit7
ST ST ST ST ST ST
Legend: ST = Schmitt Trigger input
TABLE 9-6:
Name PORTC LATC TRISC
SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Bit 7 RC7 Bit 6 RC6 Bit 5 RC5 Bit 4 RC4 Bit 3 RC3 Bit 2 RC2 Bit 1 RC1 Bit 0 RC0 Value on POR, BOR
xxxx xxxx xxxx xxxx 1111 1111
Value on All Other RESETS
uuuu uuuu uuuu uuuu 1111 1111
LATC Data Output Register PORTC Data Direction Register
Legend: x = unknown, u = unchanged
DS39564B-page 94
2002 Microchip Technology Inc.
PIC18FXX2
9.4 PORTD, TRISD and LATD Registers
FIGURE 9-8: PORTD BLOCK DIAGRAM IN I/O PORT MODE
This section is applicable only to the PIC18F4X2 devices. PORTD is an 8-bit wide, bi-directional port. The corresponding Data Direction register is TRISD. Setting a TRISD bit (= 1) will make the corresponding PORTD pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISD bit (= 0) will make the corresponding PORTD pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATD) is also memory mapped. Read-modify-write operations on the LATD register reads and writes the latched output value for PORTD. PORTD is an 8-bit port with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: On a Power-on Reset, these pins are configured as digital inputs.
RD PORTD Data Bus WR LATD or PORTD RD LATD D Q I/O pin(1) CK Data Latch D WR TRISD Q Schmitt Trigger Input Buffer
CK TRIS Latch
RD TRISD Q D EN EN
PORTD can be configured as an 8-bit wide microprocessor port (parallel slave port) by setting control bit PSPMODE (TRISE<4>). In this mode, the input buffers are TTL. See Section 9.6 for additional information on the Parallel Slave Port (PSP).
Note 1:
I/O pins have diode protection to VDD and VSS.
EXAMPLE 9-4:
CLRF PORTD ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTD
Initialize PORTD by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RD<3:0> as inputs RD<5:4> as outputs RD<7:6> as inputs
CLRF
LATD
MOVLW 0xCF
MOVWF TRISD
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PIC18FXX2
TABLE 9-7:
Name RD0/PSP0 RD1/PSP1 RD2/PSP2 RD3/PSP3 RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7
PORTD FUNCTIONS
Bit# bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type ST/TTL(1) ST/TTL(1) ST/TTL(1) ST/TTL ST/TTL
(1)
Function Input/output port pin or parallel slave port bit0. Input/output port pin or parallel slave port bit1. Input/output port pin or parallel slave port bit2. Input/output port pin or parallel slave port bit3. Input/output port pin or parallel slave port bit4. Input/output port pin or parallel slave port bit5. Input/output port pin or parallel slave port bit6. Input/output port pin or parallel slave port bit7.
ST/TTL(1)
(1)
ST/TTL(1) ST/TTL(1)
Legend: ST = Schmitt Trigger input, TTL = TTL input Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffer when in Parallel Slave Port mode.
TABLE 9-8:
Name PORTD LATD TRISD TRISE Bit 7 RD7
SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
Bit 6 RD6 Bit 5 RD5 Bit 4 RD4 Bit 3 RD3 Bit 2 RD2 Bit 1 RD1 Bit 0 RD0 Value on POR, BOR
xxxx xxxx xxxx xxxx 1111 1111
Value on All Other RESETS
uuuu uuuu uuuu uuuu 1111 1111 0000 -111
LATD Data Output Register PORTD Data Direction Register IBF OBF IBOV PSPMODE -- PORTE Data Direction bits
0000 -111
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTD.
DS39564B-page 96
2002 Microchip Technology Inc.
PIC18FXX2
9.5 PORTE, TRISE and LATE Registers
FIGURE 9-9: PORTE BLOCK DIAGRAM IN I/O PORT MODE
This section is only applicable to the PIC18F4X2 devices. PORTE is a 3-bit wide, bi-directional port. The corresponding Data Direction register is TRISE. Setting a TRISE bit (= 1) will make the corresponding PORTE pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISE bit (= 0) will make the corresponding PORTE pin an output (i.e., put the contents of the output latch on the selected pin). The Data Latch register (LATE) is also memory mapped. Read-modify-write operations on the LATE register reads and writes the latched output value for PORTE. PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6 and RE2/CS/AN7) which are individually configurable as inputs or outputs. These pins have Schmitt Trigger input buffers. Register 9-1 shows the TRISE register, which also controls the parallel slave port operation. PORTE pins are multiplexed with analog inputs. When selected as an analog input, these pins will read as '0's. TRISE controls the direction of the RE pins, even when they are being used as analog inputs. The user must make sure to keep the pins configured as inputs when using them as analog inputs. Note: On a Power-on Reset, these pins are configured as analog inputs.
RD PORTE To Analog Converter RD LATE Data Bus WR LATE or PORTE D Q I/O pin(1) CK Data Latch D WR TRISE Q Schmitt Trigger Input Buffer
CK TRIS Latch
RD TRISE Q D EN EN
Note 1:
I/O pins have diode protection to VDD and VSS.
EXAMPLE 9-5:
CLRF PORTE ; ; ; ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTE
Initialize PORTE by clearing output data latches Alternate method to clear output data latches Configure A/D for digital inputs Value used to initialize data direction Set RE<0> as inputs RE<1> as outputs RE<2> as inputs
CLRF
LATE
MOVLW MOVWF MOVLW
0x07 ADCON1 0x05
MOVWF
TRISE
2002 Microchip Technology Inc.
DS39564B-page 97
PIC18FXX2
REGISTER 9-1: TRISE REGISTER
R-0 IBF bit 7 bit 7 IBF: Input Buffer Full Status bit 1 = A word has been received and waiting to be read by the CPU 0 = No word has been received OBF: Output Buffer Full Status bit 1 = The output buffer still holds a previously written word 0 = The output buffer has been read IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode) 1 = A write occurred when a previously input word has not been read (must be cleared in software) 0 = No overflow occurred PSPMODE: Parallel Slave Port Mode Select bit 1 = Parallel Slave Port mode 0 = General purpose I/O mode Unimplemented: Read as '0' TRISE2: RE2 Direction Control bit 1 = Input 0 = Output TRISE1: RE1 Direction Control bit 1 = Input 0 = Output TRISE0: RE0 Direction Control bit 1 = Input 0 = Output Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R-0 OBF R/W-0 IBOV R/W-0 PSPMODE U-0 -- R/W-1 TRISE2 R/W-1 TRISE1 R/W-1 TRISE0 bit 0
bit 6
bit 5
bit 4
bit 3 bit 2
bit 1
bit 0
DS39564B-page 98
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 9-9:
Name
PORTE FUNCTIONS
Bit# Buffer Type Function Input/output port pin or read control input in Parallel Slave Port mode or analog input: RD 1 = Not a read operation 0 = Read operation. Reads PORTD register (if chip selected). Input/output port pin or write control input in Parallel Slave Port mode or analog input: WR 1 = Not a write operation 0 = Write operation. Writes PORTD register (if chip selected). Input/output port pin or chip select control input in Parallel Slave Port mode or analog input: CS 1 = Device is not selected 0 = Device is selected
RE0/RD/AN5
bit0
ST/TTL(1)
RE1/WR/AN6
bit1
ST/TTL(1)
RE2/CS/AN7
bit2
ST/TTL(1)
Legend: ST = Schmitt Trigger input, TTL = TTL input Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.
TABLE 9-10:
Name PORTE LATE TRISE ADCON1 Bit 7 -- -- IBF ADFM
SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Bit 6 -- -- OBF ADCS2 Bit 5 -- -- IBOV -- Bit 4 -- -- PSPMODE -- Bit 3 -- -- -- PCFG3 Bit 2 RE2 Bit 1 RE1 Bit 0 RE0 Value on POR, BOR
---- -000 ---- -xxx 0000 -111 00-- 0000
Value on All Other RESETS
---- -000 ---- -uuu 0000 -111 00-- 0000
LATE Data Output Register PORTE Data Direction bits PCFG2 PCFG1 PCFG0
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTE.
2002 Microchip Technology Inc.
DS39564B-page 99
PIC18FXX2
9.6 Parallel Slave Port
FIGURE 9-10:
The Parallel Slave Port is implemented on the 40-pin devices only (PIC18F4X2). PORTD operates as an 8-bit wide Parallel Slave Port, or microprocessor port when control bit, PSPMODE (TRISE<4>) is set. It is asynchronously readable and writable by the external world through RD control input pin, RE0/RD and WR control input pin, RE1/WR. It can directly interface to an 8-bit microprocessor data bus. The external microprocessor can read or write the PORTD latch as an 8-bit latch. Setting bit PSPMODE enables port pin RE0/RD to be the RD input, RE1/WR to be the WR input and RE2/CS to be the CS (chip select) input. For this functionality, the corresponding data direction bits of the TRISE register (TRISE<2:0>) must be configured as inputs (set). The A/D port configuration bits PCFG2:PCFG0 (ADCON1<2:0>) must be set, which will configure pins RE2:RE0 as digital I/O. A write to the PSP occurs when both the CS and WR lines are first detected low. A read from the PSP occurs when both the CS and RD lines are first detected low. The PORTE I/O pins become control inputs for the microprocessor port when bit PSPMODE (TRISE<4>) is set. In this mode, the user must make sure that the TRISE<2:0> bits are set (pins are configured as digital inputs), and the ADCON1 is configured for digital I/O. In this mode, the input buffers are TTL.
PORTD AND PORTE BLOCK DIAGRAM (PARALLEL SLAVE PORT)
Data Bus
D Q
WR LATD or PORTD
CK
RDx Pin TTL
Data Latch Q D EN EN TRIS Latch
RD PORTD
RD LATD
One bit of PORTD Set Interrupt Flag PSPIF (PIR1<7>)
Read
TTL
RD
Chip Select TTL Write TTL
CS
WR
Note: I/O pin has protection diodes to VDD and VSS.
FIGURE 9-11:
PARALLEL SLAVE PORT WRITE WAVEFORMS
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
CS WR RD PORTD<7:0> IBF OBF PSPIF
DS39564B-page 100
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 9-12: PARALLEL SLAVE PORT READ WAVEFORMS
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
CS WR RD PORTD<7:0> IBF OBF PSPIF
TABLE 9-11:
Name PORTD LATD TRISD PORTE LATE TRISE INTCON PIR1 PIE1 IPR1 ADCON1 Bit 7
REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
xxxx xxxx xxxx xxxx 1111 1111
Value on All Other RESETS
uuuu uuuu uuuu uuuu 1111 1111 ---- -000 ---- -uuu 0000 -111 0000 000u 0000 0000 0000 0000 0000 0000 00-- 0000
Port Data Latch when written; Port pins when read LATD Data Output bits PORTD Data Direction bits -- -- IBF GIE/ GIEH PSPIF PSPIE PSPIP ADFM -- -- OBF PEIE/ GIEL ADIF ADIE ADIP ADCS2 -- -- IBOV TMR0IF RCIF RCIE RCIP -- -- -- PSPMODE INT0IE TXIF TXIE TXIP -- -- -- -- RBIE SSPIF SSPIE SSPIP PCFG3 RE2 RE1 RE0 LATE Data Output bits PORTE Data Direction bits TMR0IF CCP1IF CCP1IE CCP1IP PCFG2 INT0IF TMR2IF TMR2IE TMR2IP PCFG1 RBIF TMR1IF TMR1IE TMR1IP PCFG0
---- -000 ---- -xxx 0000 -111 0000 000x 0000 0000 0000 0000 0000 0000 00-- 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Parallel Slave Port.
2002 Microchip Technology Inc.
DS39564B-page 101
PIC18FXX2
NOTES:
DS39564B-page 102
2002 Microchip Technology Inc.
PIC18FXX2
10.0 TIMER0 MODULE
The Timer0 module has the following features: * Software selectable as an 8-bit or 16-bit timer/ counter * Readable and writable * Dedicated 8-bit software programmable prescaler * Clock source selectable to be external or internal * Interrupt-on-overflow from FFh to 00h in 8-bit mode and FFFFh to 0000h in 16-bit mode * Edge select for external clock Figure 10-1 shows a simplified block diagram of the Timer0 module in 8-bit mode and Figure 10-2 shows a simplified block diagram of the Timer0 module in 16-bit mode. The T0CON register (Register 10-1) is a readable and writable register that controls all the aspects of Timer0, including the prescale selection.
REGISTER 10-1:
T0CON: TIMER0 CONTROL REGISTER
R/W-1 TMR0ON bit 7 R/W-1 T08BIT R/W-1 T0CS R/W-1 T0SE R/W-1 PSA R/W-1 T0PS2 R/W-1 T0PS1 R/W-1 T0PS0 bit 0
bit 7
TMR0ON: Timer0 On/Off Control bit 1 = Enables Timer0 0 = Stops Timer0 T08BIT: Timer0 8-bit/16-bit Control bit 1 = Timer0 is configured as an 8-bit timer/counter 0 = Timer0 is configured as a 16-bit timer/counter T0CS: Timer0 Clock Source Select bit 1 = Transition on T0CKI pin 0 = Internal instruction cycle clock (CLKO) T0SE: Timer0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin PSA: Timer0 Prescaler Assignment bit 1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler. 0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output. T0PS2:T0PS0: Timer0 Prescaler Select bits 111 = 1:256 prescale value 110 = 1:128 prescale value 101 = 1:64 prescale value 100 = 1:32 prescale value 011 = 1:16 prescale value 010 = 1:8 prescale value 001 = 1:4 prescale value 000 = 1:2 prescale value Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2-0
2002 Microchip Technology Inc.
DS39564B-page 103
PIC18FXX2
FIGURE 10-1: TIMER0 BLOCK DIAGRAM IN 8-BIT MODE
Data Bus FOSC/4 0 8 1 1 RA4/T0CKI pin T0SE Programmable Prescaler 0 Sync with Internal Clocks (2 TCY delay) TMR0L
3
T0PS2, T0PS1, T0PS0 T0CS
PSA
Set Interrupt Flag bit TMR0IF on Overflow
Note:
Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
FIGURE 10-2:
TIMER0 BLOCK DIAGRAM IN 16-BIT MODE
FOSC/4
0 1 1 Sync with Internal Clocks (2 TCY delay) TMR0L TMR0 High Byte 8 Set Interrupt Flag bit TMR0IF on Overflow
T0CKI pin T0SE
Programmable Prescaler 3
0
T0PS2, T0PS1, T0PS0 T0CS PSA 8 8 TMR0H 8
Read TMR0L Write TMR0L
Data Bus<7:0> Note: Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
DS39564B-page 104
2002 Microchip Technology Inc.
PIC18FXX2
10.1 Timer0 Operation
10.2.1 SWITCHING PRESCALER ASSIGNMENT Timer0 can operate as a timer or as a counter. Timer mode is selected by clearing the T0CS bit. In Timer mode, the Timer0 module will increment every instruction cycle (without prescaler). If the TMR0L register is written, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0L register. Counter mode is selected by setting the T0CS bit. In Counter mode, Timer0 will increment, either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit (T0SE). Clearing the T0SE bit selects the rising edge. Restrictions on the external clock input are discussed below. When an external clock input is used for Timer0, it must meet certain requirements. The requirements ensure the external clock can be synchronized with the internal phase clock (TOSC). Also, there is a delay in the actual incrementing of Timer0 after synchronization. The prescaler assignment is fully under software control, (i.e., it can be changed "on-the-fly" during program execution).
10.3
Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF bit. The interrupt can be masked by clearing the TMR0IE bit. The TMR0IE bit must be cleared in software by the Timer0 module Interrupt Service Routine before re-enabling this interrupt. The TMR0 interrupt cannot awaken the processor from SLEEP, since the timer is shut-off during SLEEP.
10.4
16-Bit Mode Timer Reads and Writes
10.2
Prescaler
An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not readable or writable. The PSA and T0PS2:T0PS0 bits determine the prescaler assignment and prescale ratio. Clearing bit PSA will assign the prescaler to the Timer0 module. When the prescaler is assigned to the Timer0 module, prescale values of 1:2, 1:4,..., 1:256 are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0L register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, x....etc.) will clear the prescaler count. Note: Writing to TMR0L when the prescaler is assigned to Timer0 will clear the prescaler count, but will not change the prescaler assignment.
TMR0H is not the high byte of the timer/counter in 16-bit mode, but is actually a buffered version of the high byte of Timer0 (refer to Figure 10-2). The high byte of the Timer0 counter/timer is not directly readable nor writable. TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16-bits of Timer0 without having to verify that the read of the high and low byte were valid due to a rollover between successive reads of the high and low byte. A write to the high byte of Timer0 must also take place through the TMR0H buffer register. Timer0 high byte is updated with the contents of TMR0H when a write occurs to TMR0L. This allows all 16-bits of Timer0 to be updated at once.
TABLE 10-1:
Name TMR0L TMR0H INTCON T0CON TRISA
REGISTERS ASSOCIATED WITH TIMER0
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
xxxx xxxx 0000 0000
Bit 7
Value on All Other RESETS
uuuu uuuu 0000 0000 0000 000u 1111 1111 -111 1111
Timer0 Module Low Byte Register Timer0 Module High Byte Register GIE/GIEH TMR0ON -- PEIE/GIEL T08BIT TMR0IE T0CS INT0IE T0SE RBIE PSA TMR0IF T0PS2 INT0IF T0PS1 RBIF T0PS0
0000 000x 1111 1111 -111 1111
PORTA Data Direction Register
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0.
2002 Microchip Technology Inc.
DS39564B-page 105
PIC18FXX2
NOTES:
DS39564B-page 106
2002 Microchip Technology Inc.
PIC18FXX2
11.0 TIMER1 MODULE
Figure 11-1 is a simplified block diagram of the Timer1 module. Register 11-1 details the Timer1 control register. This register controls the Operating mode of the Timer1 module, and contains the Timer1 oscillator enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit TMR1ON (T1CON<0>). The Timer1 module timer/counter has the following features: * 16-bit timer/counter (two 8-bit registers; TMR1H and TMR1L) * Readable and writable (both registers) * Internal or external clock select * Interrupt-on-overflow from FFFFh to 0000h * RESET from CCP module special event trigger
REGISTER 11-1:
T1CON: TIMER1 CONTROL REGISTER
R/W-0 RD16 bit 7 U-0 -- R/W-0 T1CKPS1 R/W-0 T1CKPS0 R/W-0 T1OSCEN R/W-0 T1SYNC R/W-0 TMR1CS R/W-0 TMR1ON bit 0
bit 7
RD16: 16-bit Read/Write Mode Enable bit 1 = Enables register Read/Write of Timer1 in one 16-bit operation 0 = Enables register Read/Write of Timer1 in two 8-bit operations Unimplemented: Read as '0' T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value T1OSCEN: Timer1 Oscillator Enable bit 1 = Timer1 Oscillator is enabled 0 = Timer1 Oscillator is shut-off The oscillator inverter and feedback resistor are turned off to eliminate power drain. T1SYNC: Timer1 External Clock Input Synchronization Select bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge) 0 = Internal clock (FOSC/4) TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1 Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6 bit 5-4
bit 3
bit 2
bit 1
bit 0
2002 Microchip Technology Inc.
DS39564B-page 107
PIC18FXX2
11.1 Timer1 Operation
Timer1 can operate in one of these modes: * As a timer * As a synchronous counter * As an asynchronous counter The Operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). When TMR1CS = 0, Timer1 increments every instruction cycle. When TMR1CS = 1, Timer1 increments on every rising edge of the external clock input or the Timer1 oscillator, if enabled. When the Timer1 oscillator is enabled (T1OSCEN is set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins become inputs. That is, the TRISC<1:0> value is ignored, and the pins are read as `0'. Timer1 also has an internal "RESET input". This RESET can be generated by the CCP module (Section 14.0).
FIGURE 11-1:
TMR1IF Overflow Interrupt Flag Bit
TIMER1 BLOCK DIAGRAM
CCP Special Event Trigger TMR1 TMR1H CLR TMR1L TMR1ON On/Off 0 1 T1SYNC Prescaler 1, 2, 4, 8 0 2 T1CKPS1:T1CKPS0 TMR1CS SLEEP Input Synchronize det Synchronized Clock Input
T1CKI/T1OSO T1OSI
T1OSC T1OSCEN Enable Oscillator(1) FOSC/4 Internal Clock
1
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
FIGURE 11-2:
Data Bus<7:0>
TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE
8
TMR1H
8 Write TMR1L Read TMR1L TMR1IF Overflow Interrupt Flag bit 8 Timer 1 High Byte TMR1
8 CCP Special Event Trigger Synchronized Clock Input
0 CLR TMR1L 1 TMR1ON on/off 1 T1SYNC
T1OSC T13CKI/T1OSO T1OSCEN Enable Oscillator(1)
T1OSI
FOSC/4 Internal Clock
Prescaler 1, 2, 4, 8 0 2 TMR1CS T1CKPS1:T1CKPS0
Synchronize det
SLEEP Input
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
DS39564B-page 108
2002 Microchip Technology Inc.
PIC18FXX2
11.2 Timer1 Oscillator 11.4
A crystal oscillator circuit is built-in between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting control bit T1OSCEN (T1CON<3>). The oscillator is a low power oscillator rated up to 200 kHz. It will continue to run during SLEEP. It is primarily intended for a 32 kHz crystal. Table 11-1 shows the capacitor selection for the Timer1 oscillator. The user must provide a software time delay to ensure proper start-up of the Timer1 oscillator.
Resetting Timer1 using a CCP Trigger Output
If the CCP module is configured in Compare mode to generate a "special event trigger" (CCP1M3:CCP1M0 = 1011), this signal will reset Timer1 and start an A/D conversion (if the A/D module is enabled). Note: The special event triggers from the CCP1 module will not set interrupt flag bit TMR1IF (PIR1<0>).
TABLE 11-1:
CAPACITOR SELECTION FOR THE ALTERNATE OSCILLATOR
Freq 32 kHz C1 TBD(1) C2 TBD(1) 20 PPM
Timer1 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer1 is running in Asynchronous Counter mode, this RESET operation may not work. In the event that a write to Timer1 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPR1H:CCPR1L registers pair effectively becomes the period register for Timer1.
Osc Type LP
Crystal to be Tested: 32.768 kHz Epson C-001R32.768K-A
Note 1: Microchip suggests 33 pF as a starting point in validating the oscillator circuit. 2: Higher capacitance increases the stability of the oscillator, but also increases the start-up time. 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Capacitor values are for design guidance only.
11.5
Timer1 16-Bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes (see Figure 11-2). When the RD16 control bit (T1CON<7>) is set, the address for TMR1H is mapped to a buffer register for the high byte of Timer1. A read from TMR1L will load the contents of the high byte of Timer1 into the Timer1 high byte buffer. This provides the user with the ability to accurately read all 16-bits of Timer1 without having to determine whether a read of the high byte followed by a read of the low byte is valid, due to a rollover between reads. A write to the high byte of Timer1 must also take place through the TMR1H buffer register. Timer1 high byte is updated with the contents of TMR1H when a write occurs to TMR1L. This allows a user to write all 16 bits to both the high and low bytes of Timer1 at once. The high byte of Timer1 is not directly readable or writable in this mode. All reads and writes must take place through the Timer1 high byte buffer register. Writes to TMR1H do not clear the Timer1 prescaler. The prescaler is only cleared on writes to TMR1L.
11.3
Timer1 Interrupt
The TMR1 Register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR1 Interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit TMR1IF (PIR1<0>). This interrupt can be enabled/disabled by setting/ clearing TMR1 interrupt enable bit, TMR1IE (PIE1<0>).
2002 Microchip Technology Inc.
DS39564B-page 109
PIC18FXX2
TABLE 11-2:
Name INTCON PIR1 PIE1 IPR1 TMR1L TMR1H T1CON Legend: Bit 7
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Bit 6 Bit 5 TMR0IE RCIF RCIE RCIP Bit 4 INT0IE TXIF TXIE TXIP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Value on POR, BOR Value on All Other RESETS
GIE/GIEH PEIE/GIEL PSPIF(1) PSPIE(1) PSPIP
(1)
0000 000x 0000 000u 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
ADIF ADIE ADIP
Holding Register for the Least Significant Byte of the 16-bit TMR1 Register Holding Register for the Most Significant Byte of the 16-bit TMR1 Register RD16 --
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
DS39564B-page 110
2002 Microchip Technology Inc.
PIC18FXX2
12.0
* * * * * * *
TIMER2 MODULE
12.1
Timer2 Operation
The Timer2 module timer has the following features: 8-bit timer (TMR2 register) 8-bit period register (PR2) Readable and writable (both registers) Software programmable prescaler (1:1, 1:4, 1:16) Software programmable postscaler (1:1 to 1:16) Interrupt on TMR2 match of PR2 SSP module optional use of TMR2 output to generate clock shift
Timer2 can be used as the PWM time-base for the PWM mode of the CCP module. The TMR2 register is readable and writable, and is cleared on any device RESET. The input clock (FOSC/4) has a prescale option of 1:1, 1:4 or 1:16, selected by control bits T2CKPS1:T2CKPS0 (T2CON<1:0>). The match output of TMR2 goes through a 4-bit postscaler (which gives a 1:1 to 1:16 scaling inclusive) to generate a TMR2 interrupt (latched in flag bit TMR2IF, (PIR1<1>)). The prescaler and postscaler counters are cleared when any of the following occurs: * a write to the TMR2 register * a write to the T2CON register * any device RESET (Power-on Reset, MCLR Reset, Watchdog Timer Reset, or Brown-out Reset) TMR2 is not cleared when T2CON is written.
Timer2 has a control register shown in Register 12-1. Timer2 can be shut-off by clearing control bit TMR2ON (T2CON<2>) to minimize power consumption. Figure 12-1 is a simplified block diagram of the Timer2 module. Register 12-1 shows the Timer2 control register. The prescaler and postscaler selection of Timer2 are controlled by this register.
REGISTER 12-1:
T2CON: TIMER2 CONTROL REGISTER
U-0 -- bit 7 R/W-0 TOUTPS3 R/W-0 TOUTPS2 R/W-0 TOUTPS1 R/W-0 TOUTPS0 R/W-0 R/W-0 R/W-0 T2CKPS0 bit 0 TMR2ON T2CKPS1
bit 7 bit 6-3
Unimplemented: Read as '0' TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale * * * 1111 = 1:16 Postscale TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16 Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 2
bit 1-0
2002 Microchip Technology Inc.
DS39564B-page 111
PIC18FXX2
12.2 Timer2 Interrupt 12.3 Output of TMR2
The Timer2 module has an 8-bit period register, PR2. Timer2 increments from 00h until it matches PR2 and then resets to 00h on the next increment cycle. PR2 is a readable and writable register. The PR2 register is initialized to FFh upon RESET. The output of TMR2 (before the postscaler) is fed to the Synchronous Serial Port module, which optionally uses it to generate the shift clock.
FIGURE 12-1:
TIMER2 BLOCK DIAGRAM
TMR2 Output(1) Sets Flag bit TMR2IF
FOSC/4
Prescaler 1:1, 1:4, 1:16 2 T2CKPS1:T2CKPS0
TMR2
RESET
Comparator EQ PR2
Postscaler 1:1 to 1:16 4
TOUTPS3:TOUTPS0 Note 1: TMR2 register output can be software selected by the SSP Module as a baud clock.
TABLE 12-1:
Name Bit 7
REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Bit 6 Bit 5 TMR0IE RCIF RCIE RCIP Bit 4 INT0IE TXIF TXIE TXIP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Value on POR, BOR Value on All Other RESETS
INTCON GIE/GIEH PEIE/GIEL PIR1 PIE1 IPR1 TMR2 T2CON PR2 PSPIF(1) PSPIE(1) PSPIP(1) -- ADIF ADIE ADIP
0000 000x 0000 000u 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
Timer2 Module Register Timer2 Period Register
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the Timer2 module. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
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2002 Microchip Technology Inc.
PIC18FXX2
13.0 TIMER3 MODULE
Figure 13-1 is a simplified block diagram of the Timer3 module. Register 13-1 shows the Timer3 control register. This register controls the Operating mode of the Timer3 module and sets the CCP clock source. Register 11-1 shows the Timer1 control register. This register controls the Operating mode of the Timer1 module, as well as contains the Timer1 oscillator enable bit (T1OSCEN), which can be a clock source for Timer3. The Timer3 module timer/counter has the following features: * 16-bit timer/counter (two 8-bit registers; TMR3H and TMR3L) * Readable and writable (both registers) * Internal or external clock select * Interrupt-on-overflow from FFFFh to 0000h * RESET from CCP module trigger
REGISTER 13-1:
T3CON: TIMER3 CONTROL REGISTER
R/W-0 RD16 bit 7 R/W-0 T3CCP2 R/W-0 T3CKPS1 R/W-0 T3CKPS0 R/W-0 T3CCP1 R/W-0 T3SYNC R/W-0 TMR3CS R/W-0 TMR3ON bit 0
bit 7
RD16: 16-bit Read/Write Mode Enable bit 1 = Enables register Read/Write of Timer3 in one 16-bit operation 0 = Enables register Read/Write of Timer3 in two 8-bit operations T3CCP2:T3CCP1: Timer3 and Timer1 to CCPx Enable bits 1x = Timer3 is the clock source for compare/capture CCP modules 01 = Timer3 is the clock source for compare/capture of CCP2, Timer1 is the clock source for compare/capture of CCP1 00 = Timer1 is the clock source for compare/capture CCP modules T3CKPS1:T3CKPS0: Timer3 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the system clock comes from Timer1/Timer3) When TMR3CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR3CS = 0: This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0. TMR3CS: Timer3 Clock Source Select bit 1 = External clock input from Timer1 oscillator or T1CKI (on the rising edge after the first falling edge) 0 = Internal clock (FOSC/4) TMR3ON: Timer3 On bit 1 = Enables Timer3 0 = Stops Timer3 Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6-3
bit 5-4
bit 2
bit 1
bit 0
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PIC18FXX2
13.1 Timer3 Operation
Timer3 can operate in one of these modes: * As a timer * As a synchronous counter * As an asynchronous counter The Operating mode is determined by the clock select bit, TMR3CS (T3CON<1>). When TMR3CS = 0, Timer3 increments every instruction cycle. When TMR3CS = 1, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. When the Timer1 oscillator is enabled (T1OSCEN is set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins become inputs. That is, the TRISC<1:0> value is ignored, and the pins are read as `0'. Timer3 also has an internal "RESET input". This RESET can be generated by the CCP module (Section 14.0).
FIGURE 13-1:
TIMER3 BLOCK DIAGRAM
TMR3IF Overflow Interrupt Flag bit TMR3H CCP Special Trigger T3CCPx CLR TMR3L 1 TMR3ON On/Off T3SYNC 0 Synchronized Clock Input
T1OSO/ T13CKI
T1OSC
(3)
1 T1OSCEN FOSC/4 Enable Internal Oscillator(1) Clock Prescaler 1, 2, 4, 8 0 2 TMR3CS T3CKPS1:T3CKPS0
Synchronize det
T1OSI
SLEEP Input
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
FIGURE 13-2:
TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE
8 TMR3H 8 8
Data Bus<7:0>
Write TMR3L Read TMR3L Set TMR3IF Flag bit on Overflow 8 Timer3 High Byte TMR3 TMR3L CLR 1 To Timer1 Clock Input T1OSO/ T13CKI T1OSC 1 T1OSCEN Enable Oscillator(1) FOSC/4 Internal Clock Prescaler 1, 2, 4, 8 0 2 T3CKPS1:T3CKPS0 TMR3CS SLEEP Input TMR3ON On/Off T3SYNC Synchronize det CCP Special Trigger T3CCPx 0 Synchronized Clock Input
T1OSI
Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
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PIC18FXX2
13.2 Timer1 Oscillator 13.4
The Timer1 oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN (T1CON<3>) bit. The oscillator is a low power oscillator rated up to 200 KHz. See Section 11.0 for further details.
Resetting Timer3 Using a CCP Trigger Output
If the CCP module is configured in Compare mode to generate a "special event trigger" (CCP1M3:CCP1M0 = 1011), this signal will reset Timer3. Note: The special event triggers from the CCP module will not set interrupt flag bit, TMR3IF (PIR1<0>).
13.3
Timer3 Interrupt
The TMR3 Register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR3 Interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR3IF (PIR2<1>). This interrupt can be enabled/disabled by setting/clearing TMR3 interrupt enable bit, TMR3IE (PIE2<1>).
Timer3 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer3 is running in Asynchronous Counter mode, this RESET operation may not work. In the event that a write to Timer3 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPR1H:CCPR1L registers pair effectively becomes the period register for Timer3.
TABLE 13-1:
Name INTCON PIR2 PIE2 IPR2 TMR3L TMR3H T1CON T3CON Legend: Bit 7 GIE/ GIEH -- -- --
REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Bit 6 PEIE/ GIEL -- -- -- Bit 5 TMR0IE -- -- -- Bit 4 INT0IE EEIF EEIE EEIP Bit 3 RBIE BCLIF BCLIE BCLIP Bit 2 TMR0IF LVDIF LVDIE LVDIP Bit 1 INT0IF TMR3IF TMR3IE TMR3IP Bit 0 RBIF CCP2IF CCP2IE CCP2IP Value on POR, BOR Value on All Other RESETS
0000 000x 0000 000u ---0 0000 ---0 0000 ---0 0000 ---0 0000 ---1 1111 ---1 1111 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
Holding Register for the Least Significant Byte of the 16-bit TMR3 Register Holding Register for the Most Significant Byte of the 16-bit TMR3 Register RD16 RD16 -- T3CCP2 T1CKPS1 T1CKPS0 T1OSCEN T3CKPS1 T3CKPS0 T3CCP1 T1SYNC T3SYNC
TMR1CS TMR1ON 0-00 0000 u-uu uuuu TMR3CS TMR3ON 0000 0000 uuuu uuuu
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.
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PIC18FXX2
NOTES:
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PIC18FXX2
14.0 CAPTURE/COMPARE/PWM (CCP) MODULES
The operation of CCP1 is identical to that of CCP2, with the exception of the special event trigger. Therefore, operation of a CCP module in the following sections is described with respect to CCP1. Table 14-2 shows the interaction of the CCP modules.
Each CCP (Capture/Compare/PWM) module contains a 16-bit register which can operate as a 16-bit Capture register, as a 16-bit Compare register or as a PWM Master/Slave Duty Cycle register. Table 14-1 shows the timer resources of the CCP Module modes.
REGISTER 14-1:
CCP1CON REGISTER/CCP2CON REGISTER
U-0 -- bit 7 U-0 -- R/W-0 DCxB1 R/W-0 DCxB0 R/W-0 CCPxM3 R/W-0 CCPxM2 R/W-0 R/W-0 bit 0 CCPxM1 CCPxM0
bit 7-6 bit 5-4
Unimplemented: Read as '0' DCxB1:DCxB0: PWM Duty Cycle bit1 and bit0 Capture mode: Unused Compare mode: Unused PWM mode: These bits are the two LSbs (bit1 and bit0) of the 10-bit PWM duty cycle. The upper eight bits (DCx9:DCx2) of the duty cycle are found in CCPRxL. CCPxM3:CCPxM0: CCPx Mode Select bits 0000 = Capture/Compare/PWM disabled (resets CCPx module) 0001 = Reserved 0010 = Compare mode, toggle output on match (CCPxIF bit is set) 0011 = Reserved 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode, Initialize CCP pin Low, on compare match force CCP pin High (CCPIF bit is set) 1001 = Compare mode, Initialize CCP pin High, on compare match force CCP pin Low (CCPIF bit is set) 1010 = Compare mode, Generate software interrupt on compare match (CCPIF bit is set, CCP pin is unaffected) 1011 = Compare mode, Trigger special event (CCPIF bit is set) 11xx = PWM mode Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 3-0
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PIC18FXX2
14.1 CCP1 Module 14.2 CCP2 Module
Capture/Compare/PWM Register 1 (CCPR1) is comprised of two 8-bit registers: CCPR1L (low byte) and CCPR1H (high byte). The CCP1CON register controls the operation of CCP1. All are readable and writable. Capture/Compare/PWM Register2 (CCPR2) is comprised of two 8-bit registers: CCPR2L (low byte) and CCPR2H (high byte). The CCP2CON register controls the operation of CCP2. All are readable and writable.
TABLE 14-1:
CCP MODE - TIMER RESOURCE
Timer Resource Timer1 or Timer3 Timer1 or Timer3 Timer2
CCP Mode Capture Compare PWM
TABLE 14-2:
INTERACTION OF TWO CCP MODULES
Interaction TMR1 or TMR3 time-base. Time-base can be different for each CCP. The compare could be configured for the special event trigger, which clears either TMR1 or TMR3 depending upon which time-base is used. The compare(s) could be configured for the special event trigger, which clears TMR1 or TMR3 depending upon which time-base is used. The PWMs will have the same frequency and update rate (TMR2 interrupt). None None
CCPx Mode CCPy Mode Capture Capture Compare PWM PWM PWM Capture Compare Compare PWM Capture Compare
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PIC18FXX2
14.3 Capture Mode
14.3.3 SOFTWARE INTERRUPT
In Capture mode, CCPR1H:CCPR1L captures the 16-bit value of the TMR1 or TMR3 registers when an event occurs on pin RC2/CCP1. An event is defined as one of the following: * * * * every falling edge every rising edge every 4th rising edge every 16th rising edge When the Capture mode is changed, a false capture interrupt may be generated. The user should keep bit CCP1IE (PIE1<2>) clear to avoid false interrupts and should clear the flag bit, CCP1IF, following any such change in Operating mode.
14.3.4
CCP PRESCALER
The event is selected by control bits CCP1M3:CCP1M0 (CCP1CON<3:0>). When a capture is made, the interrupt request flag bit CCP1IF (PIR1<2>) is set; it must be cleared in software. If another capture occurs before the value in register CCPR1 is read, the old captured value is overwritten by the new captured value.
There are four prescaler settings, specified by bits CCP1M3:CCP1M0. Whenever the CCP module is turned off or the CCP module is not in Capture mode, the prescaler counter is cleared. This means that any RESET will clear the prescaler counter. Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared, therefore, the first capture may be from a non-zero prescaler. Example 14-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the "false" interrupt.
14.3.1
CCP PIN CONFIGURATION
In Capture mode, the RC2/CCP1 pin should be configured as an input by setting the TRISC<2> bit. Note: If the RC2/CCP1 is configured as an output, a write to the port can cause a capture condition.
EXAMPLE 14-1:
CLRF MOVLW
CHANGING BETWEEN CAPTURE PRESCALERS
14.3.2
TIMER1/TIMER3 MODE SELECTION
The timers that are to be used with the capture feature (either Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation may not work. The timer to be used with each CCP module is selected in the T3CON register.
MOVWF
CCP1CON, F ; Turn CCP module off NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON CCP1CON ; Load CCP1CON with ; this value
FIGURE 14-1:
CAPTURE MODE OPERATION BLOCK DIAGRAM
TMR3H Set Flag bit CCP1IF Prescaler / 1, 4, 16 T3CCP2 TMR3 Enable CCPR1H and Edge Detect CCP1CON<3:0> Q's Set Flag bit CCP2IF T3CCP1 T3CCP2 Prescaler / 1, 4, 16 TMR3H TMR3 Enable CCPR2H and Edge Detect CCP2CON<3:0> Q's TMR1 Enable T3CCP2 T3CCP1 TMR1H TMR1L CCPR2L TMR3L TMR1 Enable TMR1H TMR1L CCPR1L TMR3L
CCP1 pin
T3CCP2
CCP2 pin
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PIC18FXX2
14.4 Compare Mode
14.4.2 TIMER1/TIMER3 MODE SELECTION
In Compare mode, the 16-bit CCPR1 (CCPR2) register value is constantly compared against either the TMR1 register pair value, or the TMR3 register pair value. When a match occurs, the RC2/CCP1 (RC1/CCP2) pin is: * * * * driven High driven Low toggle output (High to Low or Low to High) remains unchanged Timer1 and/or Timer3 must be running in Timer mode or Synchronized Counter mode if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work.
14.4.3
SOFTWARE INTERRUPT MODE
When generate software interrupt is chosen, the CCP1 pin is not affected. Only a CCP interrupt is generated (if enabled).
The action on the pin is based on the value of control bits CCP1M3:CCP1M0 (CCP2M3:CCP2M0). At the same time, interrupt flag bit CCP1IF (CCP2IF) is set.
14.4.4
SPECIAL EVENT TRIGGER
In this mode, an internal hardware trigger is generated, which may be used to initiate an action. The special event trigger output of CCP1 resets the TMR1 register pair. This allows the CCPR1 register to effectively be a 16-bit programmable period register for Timer1. The special trigger output of CCPx resets either the TMR1 or TMR3 register pair. Additionally, the CCP2 Special Event Trigger will start an A/D conversion if the A/D module is enabled. Note: The special event trigger from the CCP2 module will not set the Timer1 or Timer3 interrupt flag bits.
14.4.1
CCP PIN CONFIGURATION
The user must configure the CCPx pin as an output by clearing the appropriate TRISC bit. Note: Clearing the CCP1CON register will force the RC2/CCP1 compare output latch to the default low level. This is not the PORTC I/O data latch.
FIGURE 14-2:
COMPARE MODE OPERATION BLOCK DIAGRAM
Special Event Trigger will: Reset Timer1 or Timer3, but not set Timer1 or Timer3 interrupt flag bit, and set bit GO/DONE (ADCON0<2>) which starts an A/D conversion (CCP2 only) Special Event Trigger Set Flag bit CCP1IF CCPR1H CCPR1L Q RC2/CCP1 pin TRISC<2> Output Enable S R Output Logic Comparator
Match T3CCP2
CCP1CON<3:0> Mode Select
0
1
TMR1H Special Event Trigger
TMR1L
TMR3H
TMR3L
Set Flag bit CCP2IF
T3CCP1 T3CCP2
0
1
Q RC1/CCP2 pin TRISC<1> Output Enable
S R
Output Logic
Comparator Match CCPR2H CCPR2L
CCP2CON<3:0> Mode Select
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PIC18FXX2
TABLE 14-3:
Name INTCON PIR1 PIE1 IPR1 TRISC TMR1L TMR1H T1CON CCPR1L CCPR1H CCP1CON CCPR2L CCPR2H CCP2CON PIR2 PIE2 IPR2 TMR3L TMR3H T3CON Legend:
REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3
Bit 6 Bit 5 TMR0IE RCIF RCIE RCIP Bit 4 INT0IE TXIF TXIE TXIP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Value on POR, BOR Value on All Other RESETS
Bit 7
GIE/GIEH PEIE/GIEL PSPIF(1) PSPIE(1) PSPIP
(1)
0000 000x 0000 000u 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 1111 1111 1111 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
ADIF ADIE ADIP
PORTC Data Direction Register Holding Register for the Least Significant Byte of the 16-bit TMR1 Register Holding Register for the Most Significant Byte of the 16-bit TMR1 Register RD16 -- Capture/Compare/PWM Register1 (LSB) Capture/Compare/PWM Register1 (MSB) -- -- DC1B1 DC1B0 CCP1M3 Capture/Compare/PWM Register2 (LSB) Capture/Compare/PWM Register2 (MSB) -- -- -- -- -- -- -- -- DC2B1 -- -- -- DC2B0 EEIE EEIF EEIP CCP2M3 BCLIF BCLIE BCLIP LVDIF LVDIE LVDIP TMR3IF TMR3IE TMR3IP CCP2IF CCP2IE CCP2IP
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu
xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000
xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000
---0 0000 ---0 0000 ---0 0000 ---0 0000 ---1 1111 ---1 1111 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
Holding Register for the Least Significant Byte of the 16-bit TMR3 Register Holding Register for the Most Significant Byte of the 16-bit TMR3 Register RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1
T3SYNC TMR3CS TMR3ON 0000 0000 uuuu uuuu
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Capture and Timer1.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2x2 devices; always maintain these bits clear.
2002 Microchip Technology Inc.
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PIC18FXX2
14.5 PWM Mode
14.5.1 PWM PERIOD
In Pulse Width Modulation (PWM) mode, the CCP1 pin produces up to a 10-bit resolution PWM output. Since the CCP1 pin is multiplexed with the PORTC data latch, the TRISC<2> bit must be cleared to make the CCP1 pin an output. Note: Clearing the CCP1CON register will force the CCP1 PWM output latch to the default low level. This is not the PORTC I/O data latch. The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula: PWM period = (PR2) + 1] * 4 * TOSC * (TMR2 prescale value) PWM frequency is defined as 1 / [PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: * TMR2 is cleared * The CCP1 pin is set (exception: if PWM duty cycle = 0%, the CCP1 pin will not be set) * The PWM duty cycle is latched from CCPR1L into CCPR1H Note: The Timer2 postscaler (see Section 12.0) is not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output.
Figure 14-3 shows a simplified block diagram of the CCP module in PWM mode. For a step-by-step procedure on how to set up the CCP module for PWM operation, see Section 14.5.3.
FIGURE 14-3:
SIMPLIFIED PWM BLOCK DIAGRAM
CCP1CON<5:4>
Duty Cycle Registers CCPR1L
14.5.2
PWM DUTY CYCLE
CCPR1H (Slave)
Comparator
R
Q RC2/CCP1
TMR2
(Note 1) S
The PWM duty cycle is specified by writing to the CCPR1L register and to the CCP1CON<5:4> bits. Up to 10-bit resolution is available. The CCPR1L contains the eight MSbs and the CCP1CON<5:4> contains the two LSbs. This 10-bit value is represented by CCPR1L:CCP1CON<5:4>. The following equation is used to calculate the PWM duty cycle in time: PWM duty cycle = (CCPR1L:CCP1CON<5:4>) * TOSC * (TMR2 prescale value) CCPR1L and CCP1CON<5:4> can be written to at any time, but the duty cycle value is not latched into CCPR1H until after a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR1H is a read only register. The CCPR1H register and a 2-bit internal latch are used to double buffer the PWM duty cycle. This double buffering is essential for glitchless PWM operation. When the CCPR1H and 2-bit latch match TMR2 concatenated with an internal 2-bit Q clock or 2 bits of the TMR2 prescaler, the CCP1 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the equation: FOSC log --------------- FPWM PWM Resolution (max) = -----------------------------bits log ( 2 )
Comparator Clear Timer, CCP1 pin and latch D.C.
TRISC<2>
PR2
Note: 8-bit timer is concatenated with 2-bit internal Q clock or 2 bits of the prescaler to create 10-bit time-base.
A PWM output (Figure 14-4) has a time-base (period) and a time that the output stays high (duty cycle). The frequency of the PWM is the inverse of the period (1/period).
FIGURE 14-4:
Period
PWM OUTPUT
Duty Cycle TMR2 = PR2 TMR2 = Duty Cycle TMR2 = PR2
Note:
If the PWM duty cycle value is longer than the PWM period, the CCP1 pin will not be cleared.
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PIC18FXX2
14.5.3 SETUP FOR PWM OPERATION
3. 4. 5. The following steps should be taken when configuring the CCP module for PWM operation: 1. 2. Set the PWM period by writing to the PR2 register. Set the PWM duty cycle by writing to the CCPR1L register and CCP1CON<5:4> bits. Make the CCP1 pin an output by clearing the TRISC<2> bit. Set the TMR2 prescale value and enable Timer2 by writing to T2CON. Configure the CCP1 module for PWM operation.
TABLE 14-4:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
2.44 kHz 16 0xFF 14 9.77 kHz 4 0xFF 12 39.06 kHz 1 0xFF 10 156.25 kHz 1 0x3F 8 312.50 kHz 1 0x1F 7 416.67 kHz 1 0x17 6.58
PWM Frequency Timer Prescaler (1, 4, 16) PR2 Value Maximum Resolution (bits)
TABLE 14-5:
Name INTCON PIR1 PIE1 IPR1 TRISC TMR2 PR2 T2CON CCPR1L CCPR1H CCP1CON CCPR2L CCPR2H CCP2CON
REGISTERS ASSOCIATED WITH PWM AND TIMER2
Bit 6 Bit 5 TMR0IE RCIF RCIE RCIP Bit 4 INT0IE TXIF TXIE TXIP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Value on POR, BOR Value on All Other RESETS
Bit 7
GIE/GIEH PEIE/GIEL PSPIF(1) PSPIE
(1)
0000 000x 0000 000u 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 1111 1111 1111 0000 0000 0000 0000 1111 1111 1111 1111 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
ADIF ADIE ADIP
PSPIP(1)
PORTC Data Direction Register Timer2 Module Register Timer2 Module Period Register -- Capture/Compare/PWM Register1 (LSB) Capture/Compare/PWM Register1 (MSB) -- -- DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 Capture/Compare/PWM Register2 (LSB) Capture/Compare/PWM Register2 (MSB) -- -- DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
CCP1M0 --00 0000 --00 0000
xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
CCP2M0 --00 0000 --00 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PWM and Timer2. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
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NOTES:
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PIC18FXX2
15.0 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE
Master SSP (MSSP) Module Overview 15.3 SPI Mode
The SPI mode allows 8-bits of data to be synchronously transmitted and received, simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: * Serial Data Out (SDO) - RC5/SDO * Serial Data In (SDI) - RC4/SDI/SDA * Serial Clock (SCK) - RC3/SCK/SCL/LVDIN Additionally, a fourth pin may be used when in a Slave mode of operation: * Slave Select (SS) - RA5/SS/AN4 Figure 15-1 shows the block diagram of the MSSP module when operating in SPI mode.
15.1
The Master Synchronous Serial Port (MSSP) module is a serial interface useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D converters, etc. The MSSP module can operate in one of two modes: * Serial Peripheral Interface (SPI) * Inter-Integrated Circuit (I2C) - Full Master mode - Slave mode (with general address call) The I2C interface supports the following modes in hardware: * Master mode * Multi-Master mode * Slave mode
FIGURE 15-1:
MSSP BLOCK DIAGRAM (SPI MODE)
Internal Data Bus Read SSPBUF reg Write
15.2
Control Registers
RC4/SDI/SDA SSPSR reg RC5/SDO bit0 shift clock
The MSSP module has three associated registers. These include a status register (SSPSTAT) and two control registers (SSPCON1 and SSPCON2). The use of these registers and their individual configuration bits differ significantly, depending on whether the MSSP module is operated in SPI or I2C mode. Additional details are provided under the individual sections.
RA5/SS/AN4
SS Control Enable Edge Select 2 Clock Select SSPM3:SSPM0 SMP:CKE 4 TMR2 output 2 2 Edge Select Prescaler TOSC 4, 16, 64
RC3/SCK/ SCL/LVDIN
(
)
Data to TX/RX in SSPSR TRIS bit
2002 Microchip Technology Inc.
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PIC18FXX2
15.3.1 REGISTERS
The MSSP module has four registers for SPI mode operation. These are: * * * * MSSP Control Register1 (SSPCON1) MSSP Status Register (SSPSTAT) Serial Receive/Transmit Buffer (SSPBUF) MSSP Shift Register (SSPSR) - Not directly accessible SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. In receive operations, SSPSR and SSPBUF together create a double buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. During transmission, the SSPBUF is not double buffered. A write to SSPBUF will write to both SSPBUF and SSPSR.
SSPCON1 and SSPSTAT are the control and status registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the SSPSTAT are read only. The upper two bits of the SSPSTAT are read/write.
REGISTER 15-1:
SSPSTAT: MSSP STATUS REGISTER (SPI MODE)
R/W-0 SMP bit 7 R/W-0 CKE R-0 D/A R-0 P R-0 S R-0 R/W R-0 UA R-0 BF bit 0
bit 7
SMP: Sample bit SPI Master mode: 1 = Input data sampled at end of data output time 0 = Input data sampled at middle of data output time SPI Slave mode: SMP must be cleared when SPI is used in Slave mode CKE: SPI Clock Edge Select When CKP = 0: 1 = Data transmitted on rising edge of SCK 0 = Data transmitted on falling edge of SCK When CKP = 1: 1 = Data transmitted on falling edge of SCK 0 = Data transmitted on rising edge of SCK D/A: Data/Address bit Used in I2C mode only P: STOP bit Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared. S: START bit Used in I2C mode only R/W: Read/Write bit information Used in I2C mode only UA: Update Address Used in I2C mode only BF: Buffer Full Status bit (Receive mode only) 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5 bit 4
bit 3 bit 2 bit 1 bit 0
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PIC18FXX2
REGISTER 15-2: SSPCON1: MSSP CONTROL REGISTER1 (SPI MODE)
R/W-0 WCOL bit 7 bit 7 WCOL: Write Collision Detect bit (Transmit mode only) 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision SSPOV: Receive Overflow Indicator bit SPI Slave mode: 1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode.The user must read the SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software). 0 = No overflow Note: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the SSPBUF register. R/W-0 SSPOV R/W-0 SSPEN R/W-0 CKP R/W-0 SSPM3 R/W-0 SSPM2 R/W-0 SSPM1 R/W-0 SSPM0 bit 0
bit 6
bit 5
SSPEN: Synchronous Serial Port Enable bit 1 = Enables serial port and configures SCK, SDO, SDI, and SS as serial port pins 0 = Disables serial port and configures these pins as I/O port pins Note: When enabled, these pins must be properly configured as input or output.
bit 4
CKP: Clock Polarity Select bit 1 = IDLE state for clock is a high level 0 = IDLE state for clock is a low level SSPM3:SSPM0: Synchronous Serial Port Mode Select bits 0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin 0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled 0011 = SPI Master mode, clock = TMR2 output/2 0010 = SPI Master mode, clock = FOSC/64 0001 = SPI Master mode, clock = FOSC/16 0000 = SPI Master mode, clock = FOSC/4 Note: Bit combinations not specifically listed here are either reserved, or implemented in I2C mode only.
bit 3-0
Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
2002 Microchip Technology Inc.
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PIC18FXX2
15.3.2 OPERATION
When initializing the SPI, several options need to be specified. This is done by programming the appropriate control bits (SSPCON1<5:0>) and SSPSTAT<7:6>. These control bits allow the following to be specified: Master mode (SCK is the clock output) Slave mode (SCK is the clock input) Clock Polarity (IDLE state of SCK) Data input sample phase (middle or end of data output time) * Clock edge (output data on rising/falling edge of SCK) * Clock Rate (Master mode only) * Slave Select mode (Slave mode only) The MSSP consists of a transmit/receive Shift Register (SSPSR) and a buffer register (SSPBUF). The SSPSR shifts the data in and out of the device, MSb first. The SSPBUF holds the data that was written to the SSPSR, until the received data is ready. Once the 8 bits of data have been received, that byte is moved to the SSPBUF register. Then the buffer full detect bit, BF (SSPSTAT<0>), and the interrupt flag bit, SSPIF, are set. This double buffering of the received data (SSPBUF) allows the next byte to start reception before reading the data that was just received. Any write to the * * * * SSPBUF register during transmission/reception of data will be ignored, and the write collision detect bit, WCOL (SSPCON1<7>), will be set. User software must clear the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed successfully. When the application software is expecting to receive valid data, the SSPBUF should be read before the next byte of data to transfer is written to the SSPBUF. Buffer full bit, BF (SSPSTAT<0>), indicates when SSPBUF has been loaded with the received data (transmission is complete). When the SSPBUF is read, the BF bit is cleared. This data may be irrelevant if the SPI is only a transmitter. Generally, the MSSP Interrupt is used to determine when the transmission/reception has completed. The SSPBUF must be read and/or written. If the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. Example 15-1 shows the loading of the SSPBUF (SSPSR) for data transmission. The SSPSR is not directly readable or writable, and can only be accessed by addressing the SSPBUF register. Additionally, the MSSP status register (SSPSTAT) indicates the various status conditions.
EXAMPLE 15-1:
LOADING THE SSPBUF (SSPSR) REGISTER
;Has data been received(transmit complete)? ;No ;WREG reg = contents of SSPBUF ;Save in user RAM, if data is meaningful ;W reg = contents of TXDATA ;New data to xmit
LOOP BTFSS SSPSTAT, BF BRA LOOP MOVF SSPBUF, W MOVWF RXDATA MOVF TXDATA, W MOVWF SSPBUF
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PIC18FXX2
15.3.3 ENABLING SPI I/O 15.3.4 TYPICAL CONNECTION
To enable the serial port, SSP Enable bit, SSPEN (SSPCON1<5>), must be set. To reset or reconfigure SPI mode, clear the SSPEN bit, re-initialize the SSPCON registers, and then set the SSPEN bit. This configures the SDI, SDO, SCK, and SS pins as serial port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the TRIS register) appropriately programmed. That is: * SDI is automatically controlled by the SPI module * SDO must have TRISC<5> bit cleared * SCK (Master mode) must have TRISC<3> bit cleared * SCK (Slave mode) must have TRISC<3> bit set * SS must have TRISC<4> bit set Any serial port function that is not desired may be overridden by programming the corresponding data direction (TRIS) register to the opposite value. Figure 15-2 shows a typical connection between two microcontrollers. The master controller (Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both shift registers on their programmed clock edge, and latched on the opposite edge of the clock. Both processors should be programmed to the same Clock Polarity (CKP), then both controllers would send and receive data at the same time. Whether the data is meaningful (or dummy data) depends on the application software. This leads to three scenarios for data transmission: * Master sends data -- Slave sends dummy data * Master sends data -- Slave sends data * Master sends dummy data -- Slave sends data
FIGURE 15-2:
SPI MASTER/SLAVE CONNECTION
SPI Master SSPM3:SSPM0 = 00xxb SDO SDI
SPI Slave SSPM3:SSPM0 = 010xb
Serial Input Buffer (SSPBUF)
Serial Input Buffer (SSPBUF)
Shift Register (SSPSR) MSb LSb
SDI
SDO
Shift Register (SSPSR) MSb LSb
SCK PROCESSOR 1
Serial Clock
SCK PROCESSOR 2
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PIC18FXX2
15.3.5 MASTER MODE
The master can initiate the data transfer at any time because it controls the SCK. The master determines when the slave (Processor 2, Figure 15-2) is to broadcast data by the software protocol. In Master mode, the data is transmitted/received as soon as the SSPBUF register is written to. If the SPI is only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register will continue to shift in the signal present on the SDI pin at the programmed clock rate. As each byte is received, it will be loaded into the SSPBUF register as if a normal received byte (interrupts and status bits appropriately set). This could be useful in receiver applications as a "Line Activity Monitor" mode. The clock polarity is selected by appropriately programming the CKP bit (SSPCON1<4>). This then, would give waveforms for SPI communication as shown in Figure 15-3, Figure 15-5, and Figure 15-6, where the MSB is transmitted first. In Master mode, the SPI clock rate (bit rate) is user programmable to be one of the following: * * * * FOSC/4 (or TCY) FOSC/16 (or 4 * TCY) FOSC/64 (or 16 * TCY) Timer2 output/2
This allows a maximum data rate (at 40 MHz) of 10.00 Mbps. Figure 15-3 shows the waveforms for Master mode. When the CKE bit is set, the SDO data is valid before there is a clock edge on SCK. The change of the input sample is shown based on the state of the SMP bit. The time when the SSPBUF is loaded with the received data is shown.
FIGURE 15-3:
Write to SSPBUF SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) SDO (CKE = 0) SDO (CKE = 1) SDI (SMP = 0) Input Sample (SMP = 0) SDI (SMP = 1) Input Sample (SMP = 1) SSPIF SSPSR to SSPBUF
SPI MODE WAVEFORM (MASTER MODE)
4 Clock Modes
bit7 bit7
bit6 bit6
bit5 bit5
bit4 bit4
bit3 bit3
bit2 bit2
bit1 bit1
bit0 bit0
bit7
bit0
bit7
bit0
Next Q4 cycle after Q2
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2002 Microchip Technology Inc.
PIC18FXX2
15.3.6 SLAVE MODE
In Slave mode, the data is transmitted and received as the external clock pulses appear on SCK. When the last bit is latched, the SSPIF interrupt flag bit is set. While in Slave mode, the external clock is supplied by the external clock source on the SCK pin. This external clock must meet the minimum high and low times as specified in the electrical specifications. While in SLEEP mode, the slave can transmit/receive data. When a byte is received, the device will wake-up from sleep. longer driven, even if in the middle of a transmitted byte, and becomes a floating output. External pull-up/ pull-down resistors may be desirable, depending on the application. Note 1: When the SPI is in Slave mode with SS pin control enabled (SSPCON<3:0> = 0100), the SPI module will reset if the SS pin is set to VDD. 2: If the SPI is used in Slave mode with CKE set, then the SS pin control must be enabled. When the SPI module resets, the bit counter is forced to 0. This can be done by either forcing the SS pin to a high level or clearing the SSPEN bit. To emulate two-wire communication, the SDO pin can be connected to the SDI pin. When the SPI needs to operate as a receiver the SDO pin can be configured as an input. This disables transmissions from the SDO. The SDI can always be left as an input (SDI function), since it cannot create a bus conflict.
15.3.7
SLAVE SELECT SYNCHRONIZATION
The SS pin allows a Synchronous Slave mode. The SPI must be in Slave mode with SS pin control enabled (SSPCON1<3:0> = 04h). The pin must not be driven low for the SS pin to function as an input. The Data Latch must be high. When the SS pin is low, transmission and reception are enabled and the SDO pin is driven. When the SS pin goes high, the SDO pin is no
FIGURE 15-4:
SLAVE SYNCHRONIZATION WAVEFORM
SS
SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0)
Write to SSPBUF
SDO
bit7
bit6
bit7
bit0
SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF
bit0 bit7 bit7
Next Q4 cycle after Q2
2002 Microchip Technology Inc.
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PIC18FXX2
FIGURE 15-5:
SS Optional SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
bit7
bit0
Next Q4 cycle after Q2
FIGURE 15-6:
SS Not Optional SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) Write to SSPBUF SDO SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
bit7
bit0
Next Q4 cycle after Q2
DS39564B-page 132
2002 Microchip Technology Inc.
PIC18FXX2
15.3.8 SLEEP OPERATION 15.3.10 BUS MODE COMPATIBILITY
In Master mode, all module clocks are halted and the transmission/reception will remain in that state until the device wakes from SLEEP. After the device returns to Normal mode, the module will continue to transmit/ receive data. In Slave mode, the SPI transmit/receive shift register operates asynchronously to the device. This allows the device to be placed in SLEEP mode and data to be shifted into the SPI transmit/receive shift register. When all 8 bits have been received, the MSSP interrupt flag bit will be set and if enabled, will wake the device from SLEEP. Table 15-1 shows the compatibility between the standard SPI modes and the states the CKP and CKE control bits.
TABLE 15-1:
SPI BUS MODES
Control Bits State CKP 0 0 1 1 CKE 1 0 1 0
Standard SPI Mode Terminology 0, 0, 1, 1, 0 1 0 1
15.3.9
EFFECTS OF A RESET
A RESET disables the MSSP module and terminates the current transfer.
There is also a SMP bit which controls when the data is sampled.
TABLE 15-2:
Name INTCON PIR1 PIE1 IPR1 TRISC SSPBUF SSPCON TRISA SSPSTAT
REGISTERS ASSOCIATED WITH SPI OPERATION
Bit 7 Bit 6 PEIE/ GIEL ADIF ADIE ADIP Bit 5 TMR0IE RCIF RCIE RCIP Bit 4 INT0IE TXIF TXIE TXIP Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP Value on POR, BOR Value on All Other RESETS
GIE/GIEH PSPIF(1) PSPIE(1) PSPIP
(1)
0000 000x 0000 000u 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 1111 1111 1111 xxxx xxxx uuuu uuuu
PORTC Data Direction Register Synchronous Serial Port Receive Buffer/Transmit Register WCOL -- SMP SSPOV CKE SSPEN D/A CKP P SSPM3 S SSPM2 R/W SSPM1 UA SSPM0 BF PORTA Data Direction Register
0000 0000 0000 0000 -111 1111 -111 1111 0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the MSSP in SPI mode. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18C2X2 devices; always maintain these bits clear.
2002 Microchip Technology Inc.
DS39564B-page 133
PIC18FXX2
15.4 I2C Mode
15.4.1 REGISTERS
The MSSP module in I 2C mode fully implements all master and slave functions (including general call support) and provides interrupts on START and STOP bits in hardware to determine a free bus (multi-master function). The MSSP module implements the Standard mode specifications, as well as 7-bit and 10-bit addressing. Two pins are used for data transfer: * Serial clock (SCL) - RC3/SCK/SCL * Serial data (SDA) - RC4/SDI/SDA The user must configure these pins as inputs or outputs through the TRISC<4:3> bits. The MSSP module has six registers for I2C operation. These are: MSSP Control Register1 (SSPCON1) MSSP Control Register2 (SSPCON2) MSSP Status Register (SSPSTAT) Serial Receive/Transmit Buffer (SSPBUF) MSSP Shift Register (SSPSR) - Not directly accessible * MSSP Address Register (SSPADD) SSPCON, SSPCON2 and SSPSTAT are the control and status registers in I2C mode operation. The SSPCON and SSPCON2 registers are readable and writable. The lower 6 bits of the SSPSTAT are read only. The upper two bits of the SSPSTAT are read/ write. SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. SSPADD register holds the slave device address when the SSP is configured in I2C Slave mode. When the SSP is configured in Master mode, the lower seven bits of SSPADD act as the baud rate generator reload value.
LSb
* * * * *
FIGURE 15-7:
MSSP BLOCK DIAGRAM (I2C MODE)
Internal Data Bus Read SSPBUF reg Shift Clock SSPSR reg Write
RC3/SCK/SCL
RC4/ SDI/ SDA
MSb
In receive operations, SSPSR and SSPBUF together, create a double buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set.
Addr Match
Match Detect
SSPADD reg START and STOP bit Detect Set, Reset S, P bits (SSPSTAT reg)
During transmission, the SSPBUF is not double buffered. A write to SSPBUF will write to both SSPBUF and SSPSR.
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2002 Microchip Technology Inc.
PIC18FXX2
REGISTER 15-3: SSPSTAT: MSSP STATUS REGISTER (I2C MODE)
R/W-0 SMP bit 7 bit 7 SMP: Slew Rate Control bit In Master or Slave mode: 1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz) 0 = Slew rate control enabled for High Speed mode (400 kHz) CKE: SMBus Select bit In Master or Slave mode: 1 = Enable SMBus specific inputs 0 = Disable SMBus specific inputs D/A: Data/Address bit In Master mode: Reserved In Slave mode: 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address P: STOP bit 1 = Indicates that a STOP bit has been detected last 0 = STOP bit was not detected last Note: This bit is cleared on RESET and when SSPEN is cleared. S: START bit 1 = Indicates that a start bit has been detected last 0 = START bit was not detected last Note: This bit is cleared on RESET and when SSPEN is cleared. R/W: Read/Write bit Information (I2C mode only) In Slave mode: 1 = Read 0 = Write Note: This bit holds the R/W bit information following the last address match. This bit is only valid from the address match to the next START bit, STOP bit, or not ACK bit. R/W-0 CKE R-0 D/A R-0 P R-0 S R-0 R/W R-0 UA R-0 BF bit 0
bit 6
bit 5
bit 4
bit 3
bit 2
In Master mode: 1 = Transmit is in progress 0 = Transmit is not in progress Note: ORing this bit with SEN, RSEN, PEN, RCEN, or ACKEN will indicate if the MSSP is in IDLE mode. bit 1 UA: Update Address (10-bit Slave mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated BF: Buffer Full Status bit In Transmit mode: 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty In Receive mode: 1 = Data transmit in progress (does not include the ACK and STOP bits), SSPBUF is full 0 = Data transmit complete (does not include the ACK and STOP bits), SSPBUF is empty Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 0
2002 Microchip Technology Inc.
DS39564B-page 135
PIC18FXX2
REGISTER 15-4: SSPCON1: MSSP CONTROL REGISTER1 (I2C MODE)
R/W-0 WCOL bit 7 bit 7 R/W-0 SSPOV R/W-0 SSPEN R/W-0 CKP R/W-0 SSPM3 R/W-0 SSPM2 R/W-0 SSPM1 R/W-0 SSPM0 bit 0
WCOL: Write Collision Detect bit In Master Transmit mode: 1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for a transmission to be started (must be cleared in software) 0 = No collision In Slave Transmit mode: 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision In Receive mode (Master or Slave modes): This is a "don't care" bit SSPOV: Receive Overflow Indicator bit In Receive mode: 1 = A byte is received while the SSPBUF register is still holding the previous byte (must be cleared in software) 0 = No overflow In Transmit mode: This is a "don't care" bit in Transmit mode SSPEN: Synchronous Serial Port Enable bit 1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins 0 = Disables serial port and configures these pins as I/O port pins Note: When enabled, the SDA and SCL pins must be properly configured as input or output.
bit 6
bit 5
bit 4
CKP: SCK Release Control bit In Slave mode: 1 = Release clock 0 = Holds clock low (clock stretch), used to ensure data setup time In Master mode: Unused in this mode SSPM3:SSPM0: Synchronous Serial Port Mode Select bits 1111 = I2C Slave mode, 10-bit address with START and STOP bit interrupts enabled 1110 = I2C Slave mode, 7-bit address with START and STOP bit interrupts enabled 1011 = I2C Firmware Controlled Master mode (Slave IDLE) 1000 = I2C Master mode, clock = FOSC / (4 * (SSPADD+1)) 0111 = I2C Slave mode, 10-bit address 0110 = I2C Slave mode, 7-bit address Note: Bit combinations not specifically listed here are either reserved, or implemented in SPI mode only.
bit 3-0
Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
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2002 Microchip Technology Inc.
PIC18FXX2
REGISTER 15-5: SSPCON2: MSSP CONTROL REGISTER 2 (I2C MODE)
R/W-0 GCEN bit 7 bit 7 GCEN: General Call Enable bit (Slave mode only) 1 = Enable interrupt when a general call address (0000h) is received in the SSPSR 0 = General call address disabled ACKSTAT: Acknowledge Status bit (Master Transmit mode only) 1 = Acknowledge was not received from slave 0 = Acknowledge was received from slave ACKDT: Acknowledge Data bit (Master Receive mode only) 1 = Not Acknowledge 0 = Acknowledge Note: bit 4 Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive. R/W-0 ACKSTAT R/W-0 ACKDT R/W-0 ACKEN R/W-0 RCEN R/W-0 PEN R/W-0 RSEN R/W-0 SEN bit 0
bit 6
bit 5
ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only) 1 = Initiate Acknowledge sequence on SDA and SCL pins, and transmit ACKDT data bit. Automatically cleared by hardware. 0 = Acknowledge sequence IDLE RCEN: Receive Enable bit (Master mode only) 1 = Enables Receive mode for I2C 0 = Receive IDLE PEN: STOP Condition Enable bit (Master mode only) 1 = Initiate STOP condition on SDA and SCL pins. Automatically cleared by hardware. 0 = STOP condition IDLE
bit 3
bit 2
bit 1
RSEN: Repeated START Condition Enabled bit (Master mode only) 1 = Initiate Repeated START condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated START condition IDLE SEN: START Condition Enabled/Stretch Enabled bit In Master mode: 1 = Initiate START condition on SDA and SCL pins. Automatically cleared by hardware. 0 = START condition IDLE In Slave mode: 1 = Clock stretching is enabled for both Slave Transmit and Slave Receive (stretch enabled) 0 = Clock stretching is enabled for slave transmit only (Legacy mode) Note: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
bit 0
Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
2002 Microchip Technology Inc.
DS39564B-page 137
PIC18FXX2
15.4.2 OPERATION 15.4.3.1 Addressing
The MSSP module functions are enabled by setting MSSP Enable bit, SSPEN (SSPCON<5>). The SSPCON1 register allows control of the I 2C operation. Four mode selection bits (SSPCON<3:0>) allow one of the following I 2C modes to be selected: * * * * I2C Master mode, clock = OSC/4 (SSPADD +1) I 2C Slave mode (7-bit address) I 2C Slave mode (10-bit address) I 2C Slave mode (7-bit address), with START and STOP bit interrupts enabled * I 2C Slave mode (10-bit address), with START and STOP bit interrupts enabled * I 2C Firmware controlled master operation, slave is IDLE Once the MSSP module has been enabled, it waits for a START condition to occur. Following the START condition, the 8-bits are shifted into the SSPSR register. All incoming bits are sampled with the rising edge of the clock (SCL) line. The value of register SSPSR<7:1> is compared to the value of the SSPADD register. The address is compared on the falling edge of the eighth clock (SCL) pulse. If the addresses match, and the BF and SSPOV bits are clear, the following events occur: 1. 2. 3. 4. The SSPSR register value is loaded into the SSPBUF register. The buffer full bit BF is set. An ACK pulse is generated. MSSP interrupt flag bit, SSPIF (PIR1<3>) is set (interrupt is generated if enabled) on the falling edge of the ninth SCL pulse.
Selection of any I 2C mode, with the SSPEN bit set, forces the SCL and SDA pins to be open drain, provided these pins are programmed to inputs by setting the appropriate TRISC bits. To guarantee proper operation of the module, pull-up resistors must be provided externally to the SCL and SDA pins.
15.4.3
SLAVE MODE
In Slave mode, the SCL and SDA pins must be configured as inputs (TRISC<4:3> set). The MSSP module will override the input state with the output data when required (slave-transmitter). Slave mode hardware will always generate an The I interrupt on an address match. Through the mode select bits, the user can also choose to interrupt on START and STOP bits When an address is matched or the data transfer after an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse and load the SSPBUF register with the received value currently in the SSPSR register. Any combination of the following conditions will cause the MSSP module not to give this ACK pulse: * The buffer full bit BF (SSPSTAT<0>) was set before the transfer was received. * The overflow bit SSPOV (SSPCON<6>) was set before the transfer was received. In this case, the SSPSR register value is not loaded into the SSPBUF, but bit SSPIF (PIR1<3>) is set. The BF bit is cleared by reading the SSPBUF register, while bit SSPOV is cleared through software. The SCL clock input must have a minimum high and low for proper operation. The high and low times of the I2C specification, as well as the requirement of the MSSP module, are shown in timing parameter 100 and parameter 101.
2C
In 10-bit Address mode, two address bytes need to be received by the slave. The five Most Significant bits (MSbs) of the first address byte specify if this is a 10-bit address. Bit R/W (SSPSTAT<2>) must specify a write so the slave device will receive the second address byte. For a 10-bit address, the first byte would equal `11110 A9 A8 0', where `A9' and `A8' are the two MSbs of the address. The sequence of events for 10-bit address is as follows, with steps 7 through 9 for the slave-transmitter: 1. 2. Receive first (high) byte of Address (bits SSPIF, BF and bit UA (SSPSTAT<1>) are set). Update the SSPADD register with second (low) byte of Address (clears bit UA and releases the SCL line). Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. Receive second (low) byte of Address (bits SSPIF, BF, and UA are set). Update the SSPADD register with the first (high) byte of Address. If match releases SCL line, this will clear bit UA. Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. Receive Repeated START condition. Receive first (high) byte of Address (bits SSPIF and BF are set). Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF.
3. 4. 5.
6. 7. 8. 9.
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2002 Microchip Technology Inc.
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15.4.3.2 Reception
When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into the SSPBUF register and the SDA line is held low (ACK). When the address byte overflow condition exists, then the no Acknowledge (ACK) pulse is given. An overflow condition is defined as either bit BF (SSPSTAT<0>) is set, or bit SSPOV (SSPCON1<6>) is set. An MSSP interrupt is generated for each data transfer byte. Flag bit SSPIF (PIR1<3>) must be cleared in software. The SSPSTAT register is used to determine the status of the byte. If SEN is enabled (SSPCON1<0>=1), RC3/SCK/SCL will be held low (clock stretch) following each data transfer. The clock must be released by setting bit CKP (SSPCON<4>). See Section 15.4.4 ("Clock Stretching"), for more detail. The ACK pulse from the master-receiver is latched on the rising edge of the ninth SCL input pulse. If the SDA line is high (not ACK), then the data transfer is complete. In this case, when the ACK is latched by the slave, the slave logic is reset (resets SSPSTAT register) and the slave monitors for another occurrence of the START bit. If the SDA line was low (ACK), the next transmit data must be loaded into the SSPBUF register. Again, pin RC3/SCK/SCL must be enabled by setting bit CKP. An MSSP interrupt is generated for each data transfer byte. The SSPIF bit must be cleared in software and the SSPSTAT register is used to determine the status of the byte. The SSPIF bit is set on the falling edge of the ninth clock pulse.
15.4.3.3
Transmission
When the R/W bit of the incoming address byte is set and an address match occurs, the R/W bit of the SSPSTAT register is set. The received address is loaded into the SSPBUF register. The ACK pulse will be sent on the ninth bit and pin RC3/SCK/SCL is held low, regardless of SEN (see "Clock Stretching", Section 15.4.4, for more detail). By stretching the clock, the master will be unable to assert another clock pulse until the slave is done preparing the transmit data.The transmit data must be loaded into the SSPBUF register, which also loads the SSPSR register. Then pin RC3/ SCK/SCL should be enabled by setting bit CKP (SSPCON1<4>). The eight data bits are shifted out on the falling edge of the SCL input. This ensures that the SDA signal is valid during the SCL high time (Figure 15-9).
2002 Microchip Technology Inc.
DS39564B-page 139
FIGURE 15-8:
DS39564B-page 140
Receiving Address A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 R/W = 0 Receiving Data ACK Receiving Data D1 D0 ACK 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Bus Master terminates transfer Cleared in software SSPBUF is read SSPOV is set because SSPBUF is still full. ACK is not sent.
PIC18FXX2
SDA
A7
A6
SCL
S
1
2
SSPIF
(PIR1<3>)
BF (SSPSTAT<0>)
SSPOV (SSPCON<6>)
I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
2002 Microchip Technology Inc.
CKP
(CKP does not reset to `0' when SEN = 0)
FIGURE 15-9:
2002 Microchip Technology Inc.
R/W = 1 ACK D1 D0 D4 D3 D5 D7 D6 A1 D3 D2 ACK D5 D4 D7 D6 D2 Transmitting Data Transmitting Data D1 D0 ACK A4 A2 A3 4 SCL held low while CPU responds to SSPIF 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Cleared in software From SSPIF ISR SSPBUF is written in software SSPBUF is written in software Cleared in software From SSPIF ISR CKP is set in software CKP is set in software
Receiving Address
SDA
A7
A6
A5
SCL
1
2
3
S
Data in sampled
SSPIF (PIR1<3>)
BF (SSPSTAT<0>)
I2C SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
CKP
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DS39564B-page 141
FIGURE 15-10:
DS39564B-page 142
Clock is held low until update of SSPADD has taken place R/W = 0 ACK A7 D3 D2 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 ACK D7 D6 D5 D4 A0 ACK Receive Second Byte of Address Receive Data Byte Receive Data Byte D1 D0 ACK Clock is held low until update of SSPADD has taken place 0 A9 A8 5 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 6 7 8 9 P Bus Master terminates transfer Cleared in software Cleared in software Cleared in software Dummy read of SSPBUF to clear BF flag SSPOV is set because SSPBUF is still full. ACK is not sent. Cleared by hardware when SSPADD is updated with low byte of address UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address
PIC18FXX2
Receive First Byte of Address
SDA
1
1
1
1
SCL
S
1
2
3
4
SSPIF
(PIR1<3>)
Cleared in software
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
SSPOV (SSPCON<6>)
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
2002 Microchip Technology Inc.
CKP
(CKP does not reset to `0' when SEN = 0)
FIGURE 15-11:
Bus Master terminates transfer Clock is held low until CKP is set to `1' R/W=1 ACK Transmitting Data Byte D7 D6 D5 D4 D3 D2 D1 D0 ACK
2002 Microchip Technology Inc.
Clock is held low until update of SSPADD has taken place R/W = 0 Receive Second Byte of Address Receive First Byte of Address ACK 1 1 1 1 0 A9 A8 ACK A7 A6 A5 A4 A3 A2 A1 A0 1 0 A9 A8 Clock is held low until update of SSPADD has taken place 4 Sr 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Cleared in software Cleared in software Cleared in software Dummy read of SSPBUF to clear BF flag Dummy read of SSPBUF to clear BF flag Write of SSPBUF BF flag is clear initiates transmit at the end of the third address sequence Completion of data transmission clears BF flag Cleared by hardware when SSPADD is updated with low byte of address UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address. CKP is set in software CKP is automatically cleared in hardware holding SCL low
Receive First Byte of Address
SDA
1
1
1
SCL
S
1
2
3
SSPIF
(PIR1<3>)
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
I2C SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
CKP (SSPCON<4>)
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DS39564B-page 143
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15.4.4 CLOCK STRETCHING 15.4.4.3
Both 7- and 10-bit Slave modes implement automatic clock stretching during a transmit sequence. The SEN bit (SSPCON2<0>) allows clock stretching to be enabled during receives. Setting SEN will cause the SCL pin to be held low at the end of each data receive sequence.
Clock Stretching for 7-bit Slave Transmit Mode
7-bit Slave Transmit mode implements clock stretching by clearing the CKP bit after the falling edge of the ninth clock, if the BF bit is clear. This occurs, regardless of the state of the SEN bit. The user's ISR must set the CKP bit before transmission is allowed to continue. By holding the SCL line low, the user has time to service the ISR and load the contents of the SSPBUF before the master device can initiate another transmit sequence (see Figure 15-9). Note 1: If the user loads the contents of SSPBUF, setting the BF bit before the falling edge of the ninth clock, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software, regardless of the state of the BF bit.
15.4.4.1
Clock Stretching for 7-bit Slave Receive Mode (SEN = 1)
In 7-bit Slave Receive mode, on the falling edge of the ninth clock at the end of the ACK sequence, if the BF bit is set, the CKP bit in the SSPCON1 register is automatically cleared, forcing the SCL output to be held low. The CKP being cleared to `0' will assert the SCL line low. The CKP bit must be set in the user's ISR before reception is allowed to continue. By holding the SCL line low, the user has time to service the ISR and read the contents of the SSPBUF before the master device can initiate another receive sequence. This will prevent buffer overruns from occurring (see Figure 15-13). Note 1: If the user reads the contents of the SSPBUF before the falling edge of the ninth clock, thus clearing the BF bit, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software, regardless of the state of the BF bit. The user should be careful to clear the BF bit in the ISR before the next receive sequence, in order to prevent an overflow condition.
15.4.4.4
Clock Stretching for 10-bit Slave Transmit Mode
In 10-bit Slave Transmit mode, clock stretching is controlled during the first two address sequences by the state of the UA bit, just as it is in 10-bit Slave Receive mode. The first two addresses are followed by a third address sequence, which contains the high order bits of the 10-bit address and the R/W bit set to `1'. After the third address sequence is performed, the UA bit is not set, the module is now configured in Transmit mode, and clock stretching is controlled by the BF flag, as in 7-bit Slave Transmit mode (see Figure 15-11).
15.4.4.2
Clock Stretching for 10-bit Slave Receive Mode (SEN = 1)
In 10-bit Slave Receive mode, during the address sequence, clock stretching automatically takes place but CKP is not cleared. During this time, if the UA bit is set after the ninth clock, clock stretching is initiated. The UA bit is set after receiving the upper byte of the 10-bit address, and following the receive of the second byte of the 10-bit address with the R/W bit cleared to `0'. The release of the clock line occurs upon updating SSPADD. Clock stretching will occur on each data receive sequence as described in 7-bit mode. Note: If the user polls the UA bit and clears it by updating the SSPADD register before the falling edge of the ninth clock occurs, and if the user hasn't cleared the BF bit by reading the SSPBUF register before that time, then the CKP bit will still NOT be asserted low. Clock stretching on the basis of the state of the BF bit only occurs during a data sequence, not an address sequence.
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15.4.4.5 Clock Synchronization and the CKP bit
If a user clears the CKP bit, the SCL output is forced to `0'. Setting the CKP bit will not assert the SCL output low until the SCL output is already sampled low. If the user attempts to drive SCL low, the CKP bit will not assert the SCL line until an external I2C master device has already asserted the SCL line. The SCL output will remain low until the CKP bit is set, and all other devices on the I2C bus have de-asserted SCL. This ensures that a write to the CKP bit will not violate the minimum high time requirement for SCL (see Figure 15-12).
FIGURE 15-12:
CLOCK SYNCHRONIZATION TIMING
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
SDA
DX
DX-1
SCL
CKP
Master device asserts clock Master device de-asserts clock
WR SSPCON
2002 Microchip Technology Inc.
DS39564B-page 145
FIGURE 15-13:
DS39564B-page 146
Clock is not held low because buffer full bit is clear prior to falling edge of 9th clock Clock is held low until CKP is set to `1' ACK Receiving Data D7 D6 D5 D4 D3 D2 D1 D0 D2 D1 D0 Receiving Address A5 A4 A3 A2 A1 ACK D7 D6 D5 D4 D3 R/W = 0 Receiving Data Clock is not held low because ACK = 1 ACK 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 P Bus Master terminates transfer Cleared in software SSPBUF is read SSPOV is set because SSPBUF is still full. ACK is not sent.
PIC18FXX2
SDA
A7
A6
SCL
S
1
2
SSPIF
(PIR1<3>)
BF (SSPSTAT<0>)
SSPOV (SSPCON<6>)
CKP CKP written to `1' in software BF is set after falling edge of the 9th clock, CKP is reset to `0' and clock stretching occurs
I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
2002 Microchip Technology Inc.
If BF is cleared prior to the falling edge of the 9th clock, CKP will not be reset to `0' and no clock stretching will occur
FIGURE 15-14:
Clock is held low until update of SSPADD has taken place Clock is held low until CKP is set to `1' Receive Data Byte D1 D0 D7 D6 D5 D4 ACK D3 D2 R/W = 0 ACK A7 A6 A5 A4 A3 A2 A1 A0 ACK D7 D6 D5 D4 D3 D2 Receive Second Byte of Address Receive Data Byte
Clock is held low until update of SSPADD has taken place
Clock is not held low because ACK = 1 ACK D1 D0
Receive First Byte of Address A9 A8
2002 Microchip Technology Inc.
6 1 2 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 3 4 5 6 7 8 9 P Cleared in software Cleared in software Cleared in software Bus Master terminates transfer Dummy read of SSPBUF to clear BF flag Dummy read of SSPBUF to clear BF flag SSPOV is set because SSPBUF is still full. ACK is not sent. Cleared by hardware when SSPADD is updated with low byte of address after falling edge of ninth clock. UA is set indicating that SSPADD needs to be updated Note: Cleared by hardware when SSPADD is updated with high byte of address after falling edge of ninth clock. An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA, and UA will remain set. Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA, and UA will remain set. CKP written to `1' in software
SDA
1
1
1
1
0
SCL
S
1
2
3
4
5
SSPIF
(PIR1<3>)
Cleared in software
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
SSPOV (SSPCON<6>)
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
I2C SLAVE MODE TIMING SEN = 1 (RECEPTION, 10-BIT ADDRESS)
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CKP
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15.4.5 GENERAL CALL ADDRESS SUPPORT
The addressing procedure for the I2C bus is such that the first byte after the START condition usually determines which device will be the slave addressed by the master. The exception is the general call address, which can address all devices. When this address is used, all devices should, in theory, respond with an Acknowledge. The general call address is one of eight addresses reserved for specific purposes by the I2C protocol. It consists of all 0's with R/W = 0. The general call address is recognized when the General Call Enable bit (GCEN) is enabled (SSPCON2<7> set). Following a START bit detect, 8-bits are shifted into the SSPSR and the address is compared against the SSPADD. It is also compared to the general call address and fixed in hardware. If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag bit is set (eighth bit), and on the falling edge of the ninth bit (ACK bit), the SSPIF interrupt flag bit is set. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF. The value can be used to determine if the address was device specific or a general call address. In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match, and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when the GCEN bit is set, while the slave is configured in 10-bit Address mode, then the second half of the address is not necessary, the UA bit will not be set, and the slave will begin receiving data after the Acknowledge (Figure 15-15).
FIGURE 15-15:
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT ADDRESS MODE)
Address is compared to General Call Address after ACK, set interrupt R/W = 0 ACK D7 Receiving data D6 D5 D4 D3 D2 D1 D0 ACK
SDA SCL S SSPIF BF (SSPSTAT<0>) 1
General Call Address
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
Cleared in software SSPBUF is read SSPOV (SSPCON1<6>) '0'
GCEN (SSPCON2<7>)
'1'
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15.4.6 MASTER MODE
Note: Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware. Master mode of operation is supported by interrupt generation on the detection of the START and STOP conditions. The STOP (P) and START (S) bits are cleared from a RESET or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit is set or the bus is IDLE, with both the S and P bits clear. In Firmware Controlled Master mode, user code conducts all I 2C bus operations based on START and STOP bit conditions. Once Master mode is enabled, the user has six options. 1. 2. 3. 4. 5. 6. Assert a START condition on SDA and SCL. Assert a Repeated START condition on SDA and SCL. Write to the SSPBUF register initiating transmission of data/address. Configure the I2C port to receive data. Generate an Acknowledge condition at the end of a received byte of data. Generate a STOP condition on SDA and SCL. The MSSP Module, when configured in I2C Master mode, does not allow queueing of events. For instance, the user is not allowed to initiate a START condition and immediately write the SSPBUF register to initiate transmission before the START condition is complete. In this case, the SSPBUF will not be written to and the WCOL bit will be set, indicating that a write to the SSPBUF did not occur.
The following events will cause SSP interrupt flag bit, SSPIF, to be set (SSP interrupt if enabled): * * * * * START condition STOP condition Data transfer byte transmitted/received Acknowledge Transmit Repeated START
FIGURE 15-16:
MSSP BLOCK DIAGRAM (I2C MASTER MODE)
Internal Data Bus Read SSPBUF Write Baud Rate Generator Clock Arbitrate/WCOL Detect (hold off clock source) DS39564B-page 149 Shift Clock SSPSR Receive Enable MSb LSb SSPM3:SSPM0 SSPADD<6:0>
SDA SDA in
SCL
SCL in Bus Collision
START bit Detect STOP bit Detect Write Collision Detect Clock Arbitration State Counter for end of XMIT/RCV
Set/Reset, S, P, WCOL (SSPSTAT) Set SSPIF, BCLIF Reset ACKSTAT, PEN (SSPCON2)
2002 Microchip Technology Inc.
Clock Cntl
START bit, STOP bit, Acknowledge Generate
PIC18FXX2
15.4.6.1 I2C Master Mode Operation
A typical transmit sequence would go as follows: 1. The user generates a START condition by setting the START enable bit, SEN (SSPCON2<0>). 2. SSPIF is set. The MSSP module will wait the required start time before any other operation takes place. 3. The user loads the SSPBUF with the slave address to transmit. 4. Address is shifted out the SDA pin until all 8 bits are transmitted. 5. The MSSP Module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 6. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 7. The user loads the SSPBUF with eight bits of data. 8. Data is shifted out the SDA pin until all 8 bits are transmitted. 9. The MSSP Module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 10. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 11. The user generates a STOP condition by setting the STOP enable bit PEN (SSPCON2<2>). 12. Interrupt is generated once the STOP condition is complete. The master device generates all of the serial clock pulses and the START and STOP conditions. A transfer is ended with a STOP condition or with a Repeated START condition. Since the Repeated START condition is also the beginning of the next serial transfer, the I2C bus will not be released. In Master Transmitter mode, serial data is output through SDA, while SCL outputs the serial clock. The first byte transmitted contains the slave address of the receiving device (7 bits) and the Read/Write (R/W) bit. In this case, the R/W bit will be logic '0'. Serial data is transmitted 8 bits at a time. After each byte is transmitted, an Acknowledge bit is received. START and STOP conditions are output to indicate the beginning and the end of a serial transfer. In Master Receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the R/W bit. In this case, the R/W bit will be logic '1'. Thus, the first byte transmitted is a 7-bit slave address followed by a '1' to indicate receive bit. Serial data is received via SDA, while SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an Acknowledge bit is transmitted. START and STOP conditions indicate the beginning and end of transmission. The baud rate generator used for the SPI mode operation is used to set the SCL clock frequency for either 100 kHz, 400 kHz or 1 MHz I2C operation. See Section 15.4.7 ("Baud Rate Generator"), for more detail.
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15.4.7
I2C
BAUD RATE GENERATOR
In Master mode, the baud rate generator (BRG) reload value is placed in the lower 7 bits of the SSPADD register (Figure 15-17). When a write occurs to SSPBUF, the baud rate generator will automatically begin counting. The BRG counts down to 0 and stops until another reload has taken place. The BRG count is decremented twice per instruction cycle (TCY) on the Q2 and Q4 clocks. In I2C Master mode, the BRG is reloaded automatically.
Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal clock will automatically stop counting and the SCL pin will remain in its last state. Table 15-3 demonstrates clock rates based on instruction cycles and the BRG value loaded into SSPADD.
FIGURE 15-17:
BAUD RATE GENERATOR BLOCK DIAGRAM
SSPM3:SSPM0 SSPADD<6:0>
SSPM3:SSPM0 SCL
Reload Control CLKO
Reload
BRG Down Counter
Fosc/4
TABLE 15-3:
FCY
I2C CLOCK RATE W/BRG
FCY*2 20 MHz 20 MHz 20 MHz 8 MHz 8 MHz 8 MHz 2 MHz 2 MHz 2 MHz BRG Value 19h 20h 3Fh 0Ah 0Dh 28h 03h 0Ah 00h FSCL(2) (2 Rollovers of BRG) 400 kHz(1) 312.5 kHz 100 kHz 400 kHz(1) 308 kHz 100 kHz 333 kHz(1) 100kHz 1 MHz(1)
10 MHz 10 MHz 10 MHz 4 MHz 4 MHz 4 MHz 1 MHz 1 MHz 1 MHz
Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than 100 kHz) in all details, but may be used with care where higher rates are required by the application. 2: Actual frequency will depend on bus conditions. Theoretically, bus conditions will add rise time and extend low time of clock period, producing the effective frequency.
2002 Microchip Technology Inc.
DS39564B-page 151
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15.4.7.1 Clock Arbitration
Clock arbitration occurs when the master, during any receive, transmit or Repeated START/STOP condition, de-asserts the SCL pin (SCL allowed to float high). When the SCL pin is allowed to float high, the baud rate generator (BRG) is suspended from counting until the SCL pin is actually sampled high. When the SCL pin is sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. This ensures that the SCL high time will always be at least one BRG rollover count, in the event that the clock is held low by an external device (Figure 15-18).
FIGURE 15-18:
SDA
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
DX DX-1 SCL allowed to transition high
SCL de-asserted but slave holds SCL low (clock arbitration) SCL BRG decrements on Q2 and Q4 cycles BRG Value 03h 02h 01h 00h (hold off)
03h
02h
SCL is sampled high, reload takes place and BRG starts its count. BRG Reload
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PIC18FXX2
15.4.8 I2C MASTER MODE START CONDITION TIMING 15.4.8.1 WCOL Status Flag
If the user writes the SSPBUF when a START sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the START condition is complete.
To initiate a START condition, the user sets the START condition enable bit, SEN (SSPCON2<0>). If the SDA and SCL pins are sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and starts its count. If SCL and SDA are both sampled high when the baud rate generator times out (TBRG), the SDA pin is driven low. The action of the SDA being driven low, while SCL is high, is the START condition and causes the S bit (SSPSTAT<3>) to be set. Following this, the baud rate generator is reloaded with the contents of SSPADD<6:0> and resumes its count. When the baud rate generator times out (TBRG), the SEN bit (SSPCON2<0>) will be automatically cleared by hardware, the baud rate generator is suspended, leaving the SDA line held low and the START condition is complete. Note: If at the beginning of the START condition, the SDA and SCL pins are already sampled low, or if during the START condition the SCL line is sampled low before the SDA line is driven low, a bus collision occurs, the Bus Collision Interrupt Flag, BCLIF is set, the START condition is aborted, and the I2C module is reset into its IDLE state.
FIGURE 15-19:
FIRST START BIT TIMING
Set S bit (SSPSTAT<3>) SDA = 1, SCL = 1 At completion of START bit, Hardware clears SEN bit and sets SSPIF bit TBRG Write to SSPBUF occurs here 1st bit SDA TBRG 2nd bit
Write to SEN bit occurs here
TBRG
SCL S
TBRG
2002 Microchip Technology Inc.
DS39564B-page 153
PIC18FXX2
15.4.9 I2C MASTER MODE REPEATED START CONDITION TIMING
Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7-bit mode, or the default first address in 10-bit mode. After the first eight bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode) or eight bits of data (7-bit mode).
A Repeated START condition occurs when the RSEN bit (SSPCON2<1>) is programmed high and the I2C logic module is in the IDLE state. When the RSEN bit is set, the SCL pin is asserted low. When the SCL pin is sampled low, the baud rate generator is loaded with the contents of SSPADD<5:0> and begins counting. The SDA pin is released (brought high) for one baud rate generator count (TBRG). When the baud rate generator times out, if SDA is sampled high, the SCL pin will be de-asserted (brought high). When SCL is sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and SCL must be sampled high for one TBRG. This action is then followed by assertion of the SDA pin (SDA = 0) for one TBRG, while SCL is high. Following this, the RSEN bit (SSPCON2<1>) will be automatically cleared and the baud rate generator will not be reloaded, leaving the SDA pin held low. As soon as a START condition is detected on the SDA and SCL pins, the S bit (SSPSTAT<3>) will be set. The SSPIF bit will not be set until the baud rate generator has timed out. Note 1: If RSEN is programmed while any other event is in progress, it will not take effect. 2: A bus collision during the Repeated START condition occurs if: * SDA is sampled low when SCL goes from low to high. * SCL goes low before SDA is asserted low. This may indicate that another master is attempting to transmit a data "1".
15.4.9.1
WCOL Status Flag
If the user writes the SSPBUF when a Repeated START sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated START condition is complete.
FIGURE 15-20:
REPEAT START CONDITION WAVEFORM
Set S (SSPSTAT<3>) Write to SSPCON2 occurs here. SDA = 1, SCL (no change) SDA = 1, SCL = 1 At completion of START bit, hardware clear RSEN bit and set SSPIF TBRG 1st bit SDA Falling edge of ninth clock End of Xmit Write to SSPBUF occurs here TBRG TBRG Sr = Repeated START
TBRG
TBRG
SCL
DS39564B-page 154
2002 Microchip Technology Inc.
PIC18FXX2
15.4.10 I2C MASTER MODE TRANSMISSION 15.4.10.3 ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is cleared when the slave has sent an Acknowledge (ACK = 0), and is set when the slave does not Acknowledge (ACK = 1). A slave sends an Acknowledge when it has recognized its address (including a general call) or when the slave has properly received its data.
Transmission of a data byte, a 7-bit address, or the other half of a 10-bit address is accomplished by simply writing a value to the SSPBUF register. This action will set the buffer full flag bit, BF, and allow the baud rate generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto the SDA pin after the falling edge of SCL is asserted (see data hold time specification parameter 106). SCL is held low for one baud rate generator rollover count (TBRG). Data should be valid before SCL is released high (see data setup time specification parameter 107). When the SCL pin is released high, it is held that way for TBRG. The data on the SDA pin must remain stable for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the falling edge of the eighth clock), the BF flag is cleared and the master releases SDA. This allows the slave device being addressed to respond with an ACK bit during the ninth bit time if an address match occurred or if data was received properly. The status of ACK is written into the ACKDT bit on the falling edge of the ninth clock. If the master receives an Acknowledge, the Acknowledge status bit, ACKSTAT, is cleared. If not, the bit is set. After the ninth clock, the SSPIF bit is set and the master clock (baud rate generator) is suspended until the next data byte is loaded into the SSPBUF, leaving SCL low and SDA unchanged (Figure 15-21). After the write to the SSPBUF, each bit of address will be shifted out on the falling edge of SCL until all seven address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will de-assert the SDA pin, allowing the slave to respond with an Acknowledge. On the falling edge of the ninth clock, the master will sample the SDA pin to see if the address was recognized by a slave. The status of the ACK bit is loaded into the ACKSTAT status bit (SSPCON2<6>). Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is cleared and the baud rate generator is turned off until another write to the SSPBUF takes place, holding SCL low and allowing SDA to float.
15.4.11
I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the receive enable bit, RCEN (SSPCON2<3>). Note: In the MSSP module, the RCEN bit must be set after the ACK sequence or the RCEN bit will be disregarded.
The baud rate generator begins counting, and on each rollover, the state of the SCL pin changes (high to low/ low to high) and data is shifted into the SSPSR. After the falling edge of the eighth clock, the receive enable flag is automatically cleared, the contents of the SSPSR are loaded into the SSPBUF, the BF flag bit is set, the SSPIF flag bit is set and the baud rate generator is suspended from counting, holding SCL low. The MSSP is now in IDLE state, awaiting the next command. When the buffer is read by the CPU, the BF flag bit is automatically cleared. The user can then send an Acknowledge bit at the end of reception, by setting the Acknowledge sequence enable bit, ACKEN (SSPCON2<4>).
15.4.11.1
BF Status Flag
In receive operation, the BF bit is set when an address or data byte is loaded into SSPBUF from SSPSR. It is cleared when the SSPBUF register is read.
15.4.11.2
SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits are received into the SSPSR and the BF flag bit is already set from a previous reception.
15.4.11.3
WCOL Status Flag
15.4.10.1
BF Status Flag
If the user writes the SSPBUF when a receive is already in progress (i.e., SSPSR is still shifting in a data byte), the WCOL bit is set and the contents of the buffer are unchanged (the write doesn't occur).
In Transmit mode, the BF bit (SSPSTAT<0>) is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out.
15.4.10.2
WCOL Status Flag
If the user writes the SSPBUF when a transmit is already in progress (i.e., SSPSR is still shifting out a data byte), the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). WCOL must be cleared in software.
2002 Microchip Technology Inc.
DS39564B-page 155
FIGURE 15-21:
DS39564B-page 156
Write SSPCON2<0> SEN = 1 START condition begins From slave clear ACKSTAT bit SSPCON2<6> R/W = 0 A1 ACK = 0 D7 D6 D5 D4 D3 D2 D1 Transmitting Data or Second Half of 10-bit Address D0 ACK SEN = 0 Transmit Address to Slave SDA A7 SSPBUF written with 7-bit address and R/W start transmit SCL S 1 2 3 4 5 6 7 8 9 1 SCL held low while CPU responds to SSPIF 2 3 4 5 6 7 8 9 P A6 A5 A4 A3 A2 ACKSTAT in SSPCON2 = 1 SSPIF Cleared in software Cleared in software service routine From SSP interrupt Cleared in software BF (SSPSTAT<0>) SSPBUF written SEN After START condition, SEN cleared by hardware SSPBUF is written in software PEN
PIC18FXX2
I 2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
2002 Microchip Technology Inc.
R/W
FIGURE 15-22:
Write to SSPCON2<4> to start Acknowledge sequence SDA = ACKDT (SSPCON2<5>) = 0 Master configured as a receiver by programming SSPCON2<3>, (RCEN = 1) ACK from Slave R/W = 1 Receiving Data from Slave ACK Receiving Data from Slave RCEN cleared automatically ACK RCEN = 1 start next receive RCEN cleared automatically ACK from Master SDA = ACKDT = 0 Set ACKEN, start Acknowledge sequence SDA = ACKDT = 1 PEN bit = 1 written here
2002 Microchip Technology Inc.
A1 D0 D7 D6 D5 D4 D3 D2 D1 D7 D6 D5 D4 D3 D2 D1 D0
ACK ACK is not sent Bus Master terminates transfer
Write to SSPCON2<0> (SEN = 1) Begin START Condition
SEN = 0 Write to SSPBUF occurs here Start XMIT
Transmit Address to Slave
SDA
A7
A6 A5 A4 A3 A2
SCL
S
Set SSPIF interrupt at end of receive
1 5 1 2 3 4 5 1 2 3 4
2
3 4 8 6 7 8 9
6
7 9
5
6
7
8
9
Set SSPIF at end of receive
P
Set SSPIF interrupt at end of Acknowledge sequence
Data shifted in on falling edge of CLK
SSPIF
Cleared in software Cleared in software
Set SSPIF interrupt at end of Acknowledge sequence Cleared in software Cleared in software
SDA = 0, SCL = 1 while CPU responds to SSPIF
Cleared in software
Set P bit (SSPSTAT<4>) and SSPIF
BF (SSPSTAT<0>)
Last bit is shifted into SSPSR and contents are unloaded into SSPBUF
SSPOV
SSPOV is set because SSPBUF is still full
I 2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
PIC18FXX2
ACKEN
DS39564B-page 157
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15.4.12 ACKNOWLEDGE SEQUENCE TIMING 15.4.13 STOP CONDITION TIMING
An Acknowledge sequence is enabled by setting the Acknowledge sequence enable bit, ACKEN (SSPCON2<4>). When this bit is set, the SCL pin is pulled low and the contents of the Acknowledge data bit are presented on the SDA pin. If the user wishes to generate an Acknowledge, then the ACKDT bit should be cleared. If not, the user should set the ACKDT bit before starting an Acknowledge sequence. The baud rate generator then counts for one rollover period (TBRG) and the SCL pin is de-asserted (pulled high). When the SCL pin is sampled high (clock arbitration), the baud rate generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the baud rate generator is turned off and the MSSP module then goes into IDLE mode (Figure 15-23). A STOP bit is asserted on the SDA pin at the end of a receive/transmit by setting the STOP sequence enable bit, PEN (SSPCON2<2>). At the end of a receive/transmit the SCL line is held low after the falling edge of the ninth clock. When the PEN bit is set, the master will assert the SDA line low. When the SDA line is sampled low, the baud rate generator is reloaded and counts down to 0. When the baud rate generator times out, the SCL pin will be brought high, and one TBRG (baud rate generator rollover count) later, the SDA pin will be de-asserted. When the SDA pin is sampled high while SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 15-24).
15.4.13.1
WCOL Status Flag
15.4.12.1
WCOL Status Flag
If the user writes the SSPBUF when an Acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur).
If the user writes the SSPBUF when a STOP sequence is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn't occur).
FIGURE 15-23:
ACKNOWLEDGE SEQUENCE WAVEFORM
Acknowledge sequence starts here, Write to SSPCON2 ACKEN = 1, ACKDT = 0 TBRG SDA D0 ACK TBRG ACKEN automatically cleared
SCL
8
9
SSPIF Cleared in software Set SSPIF at the end of Acknowledge sequence
Set SSPIF at the end of receive Note: TBRG = one baud rate generator period.
Cleared in software
FIGURE 15-24:
STOP CONDITION RECEIVE OR TRANSMIT MODE
Write to SSPCON2 Set PEN SCL = 1 for TBRG, followed by SDA = 1 for TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set TBRG
Falling edge of 9th clock SCL
SDA
ACK P TBRG TBRG TBRG SCL brought high after TBRG SDA asserted low before rising edge of clock to setup STOP condition.
Note: TBRG = one baud rate generator period.
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2002 Microchip Technology Inc.
PIC18FXX2
15.4.14 SLEEP OPERATION
I2C
15.4.17
While in SLEEP mode, the module can receive addresses or data, and when an address match or complete byte transfer occurs, wake the processor from SLEEP (if the MSSP interrupt is enabled).
MULTI -MASTER COMMUNICATION, BUS COLLISION, AND BUS ARBITRATION
15.4.15
EFFECT OF A RESET
A RESET disables the MSSP module and terminates the current transfer.
15.4.16
MULTI-MASTER MODE
In Multi-Master mode, the interrupt generation on the detection of the START and STOP conditions allows the determination of when the bus is free. The STOP (P) and START (S) bits are cleared from a RESET or when the MSSP module is disabled. Control of the I2C bus may be taken when the P bit (SSPSTAT<4>) is set, or the bus is idle with both the S and P bits clear. When the bus is busy, enabling the SSP interrupt will generate the interrupt when the STOP condition occurs. In multi-master operation, the SDA line must be monitored for arbitration, to see if the signal level is the expected output level. This check is performed in hardware, with the result placed in the BCLIF bit. The states where arbitration can be lost are: * * * * * Address Transfer Data Transfer A START Condition A Repeated START Condition An Acknowledge Condition
Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto the SDA pin, arbitration takes place when the master outputs a '1' on SDA, by letting SDA float high and another master asserts a '0'. When the SCL pin floats high, data should be stable. If the expected data on SDA is a '1' and the data sampled on the SDA pin = '0', then a bus collision has taken place. The master will set the Bus Collision Interrupt Flag BCLIF and reset the I2C port to its IDLE state (Figure 15-25). If a transmit was in progress when the bus collision occurred, the transmission is halted, the BF flag is cleared, the SDA and SCL lines are de-asserted, and the SSPBUF can be written to. When the user services the bus collision Interrupt Service Routine, and if the I2C bus is free, the user can resume communication by asserting a START condition. If a START, Repeated START, STOP, or Acknowledge condition was in progress when the bus collision occurred, the condition is aborted, the SDA and SCL lines are de-asserted, and the respective control bits in the SSPCON2 register are cleared. When the user services the bus collision Interrupt Service Routine, and if the I2C bus is free, the user can resume communication by asserting a START condition. The master will continue to monitor the SDA and SCL pins. If a STOP condition occurs, the SSPIF bit will be set. A write to the SSPBUF will start the transmission of data at the first data bit, regardless of where the transmitter left off when the bus collision occurred. In Multi-Master mode, the interrupt generation on the detection of START and STOP conditions allows the determination of when the bus is free. Control of the I2C bus can be taken when the P bit is set in the SSPSTAT register, or the bus is IDLE and the S and P bits are cleared.
FIGURE 15-25:
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
Data changes while SCL = 0 SDA line pulled low by another source SDA released by master Sample SDA. While SCL is high, data doesn't match what is driven by the master. Bus collision has occurred.
SDA
SCL
Set bus collision interrupt (BCLIF)
BCLIF
2002 Microchip Technology Inc.
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15.4.17.1 Bus Collision During a START Condition
During a START condition, a bus collision occurs if: a) b) SDA or SCL are sampled low at the beginning of the START condition (Figure 15-26). SCL is sampled low before SDA is asserted low (Figure 15-27). If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 15-28). If, however, a '1' is sampled on the SDA pin, the SDA pin is asserted low at the end of the BRG count. The baud rate generator is then reloaded and counts down to 0, and during this time, if the SCL pins are sampled as '0', a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. Note: The reason that bus collision is not a factor during a START condition is that no two bus masters can assert a START condition at the exact same time. Therefore, one master will always assert SDA before the other. This condition does not cause a bus collision, because the two masters must be allowed to arbitrate the first address following the START condition. If the address is the same, arbitration must be allowed to continue into the data portion, Repeated START or STOP conditions.
During a START condition, both the SDA and the SCL pins are monitored. If the SDA pin is already low, or the SCL pin is already low, then all of the following occur: * the START condition is aborted, * the BCLIF flag is set, and * the MSSP module is reset to its IDLE state (Figure 15-26). The START condition begins with the SDA and SCL pins de-asserted. When the SDA pin is sampled high, the baud rate generator is loaded from SSPADD<6:0> and counts down to 0. If the SCL pin is sampled low while SDA is high, a bus collision occurs, because it is assumed that another master is attempting to drive a data '1' during the START condition.
FIGURE 15-26:
BUS COLLISION DURING START CONDITION (SDA ONLY)
SDA goes low before the SEN bit is set. Set BCLIF, S bit and SSPIF set because SDA = 0, SCL = 1.
SDA
SCL Set SEN, enable START condition if SDA = 1, SCL=1 SEN SDA sampled low before START condition. Set BCLIF. S bit and SSPIF set because SDA = 0, SCL = 1. SSPIF and BCLIF are cleared in software. S SEN cleared automatically because of bus collision. SSP module reset into IDLE state.
BCLIF
SSPIF
SSPIF and BCLIF are cleared in software.
DS39564B-page 160
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 15-27: BUS COLLISION DURING START CONDITION (SCL = 0)
SDA = 0, SCL = 1
TBRG TBRG
SDA
SCL
Set SEN, enable START sequence if SDA = 1, SCL = 1 SCL = 0 before SDA = 0, bus collision occurs. set BCLIF SCL = 0 before BRG time-out, bus collision occurs. Set BCLIF.
SEN
BCLIF Interrupt cleared in software S SSPIF '0' '0' '0' '0'
FIGURE 15-28:
BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION
SDA = 0, SCL = 1 Set S Less than TBRG
TBRG
Set SSPIF
SDA
SDA pulled low by other master. Reset BRG and assert SDA.
SCL
S
SCL pulled low after BRG Time-out Set SEN, enable START sequence if SDA = 1, SCL = 1
SEN
BCLIF
'0'
S
SSPIF SDA = 0, SCL = 1 Set SSPIF Interrupts cleared in software
2002 Microchip Technology Inc.
DS39564B-page 161
PIC18FXX2
15.4.17.2 Bus Collision During a Repeated START Condition
During a Repeated START condition, a bus collision occurs if: a) b) A low level is sampled on SDA when SCL goes from low level to high level. SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data '1'. reloaded and begins counting. If SDA goes from high to low before the BRG times out, no bus collision occurs because no two masters can assert SDA at exactly the same time. If SCL goes from high to low before the BRG times out and SDA has not already been asserted, a bus collision occurs. In this case, another master is attempting to transmit a data '1' during the Repeated START condition, Figure 15-30. If, at the end of the BRG time-out both SCL and SDA are still high, the SDA pin is driven low and the BRG is reloaded and begins counting. At the end of the count, regardless of the status of the SCL pin, the SCL pin is driven low and the Repeated START condition is complete.
When the user de-asserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD<6:0> and counts down to 0. The SCL pin is then de-asserted, and when sampled high, the SDA pin is sampled. If SDA is low, a bus collision has occurred (i.e., another master is attempting to transmit a data '0', Figure 15-29). If SDA is sampled high, the BRG is
FIGURE 15-29:
SDA
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SCL Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. RSEN BCLIF Cleared in software '0' '0'
S SSPIF
FIGURE 15-30:
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
TBRG TBRG
SDA SCL SCL goes low before SDA, Set BCLIF. Release SDA and SCL. Interrupt cleared in software RSEN S SSPIF
'0'
BCLIF
DS39564B-page 162
2002 Microchip Technology Inc.
PIC18FXX2
15.4.17.3 Bus Collision During a STOP Condition
Bus collision occurs during a STOP condition if: a) After the SDA pin has been de-asserted and allowed to float high, SDA is sampled low after the BRG has timed out. After the SCL pin is de-asserted, SCL is sampled low before SDA goes high. The STOP condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allowed to float. When the pin is sampled high (clock arbitration), the baud rate generator is loaded with SSPADD<6:0> and counts down to 0. After the BRG times out, SDA is sampled. If SDA is sampled low, a bus collision has occurred. This is due to another master attempting to drive a data '0' (Figure 15-31). If the SCL pin is sampled low before SDA is allowed to float high, a bus collision occurs. This is another case of another master attempting to drive a data '0' (Figure 15-32).
b)
FIGURE 15-31:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
TBRG TBRG TBRG
SDA sampled low after TBRG, Set BCLIF
SDA SDA asserted low SCL PEN BCLIF P SSPIF '0' '0'
FIGURE 15-32:
BUS COLLISION DURING A STOP CONDITION (CASE 2)
TBRG TBRG TBRG
SDA Assert SDA SCL PEN BCLIF P SSPIF '0' '0' SCL goes low before SDA goes high Set BCLIF
2002 Microchip Technology Inc.
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PIC18FXX2
NOTES:
DS39564B-page 164
2002 Microchip Technology Inc.
PIC18FXX2
16.0 ADDRESSABLE UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (USART)
The Universal Synchronous Asynchronous Receiver Transmitter (USART) module is one of the two serial I/O modules. (USART is also known as a Serial Communications Interface or SCI.) The USART can be configured as a full duplex asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers, or it can be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. The USART can be configured in the following modes: * Asynchronous (full-duplex) * Synchronous - Master (half-duplex) * Synchronous - Slave (half-duplex) In order to configure pins RC6/TX/CK and RC7/RX/DT as the Universal Synchronous Asynchronous Receiver Transmitter: * bit SPEN (RCSTA<7>) must be set (= 1), * bit TRISC<6> must be cleared (= 0), and * bit TRISC<7> must be set (=1). Register 16-1 shows the Transmit Status and Control Register (TXSTA) and Register 16-2 shows the Receive Status and Control Register (RCSTA).
2002 Microchip Technology Inc.
DS39564B-page 165
PIC18FXX2
REGISTER 16-1: TXSTA: TRANSMIT STATUS AND CONTROL REGISTER
R/W-0 CSRC bit 7 bit 7 R/W-0 TX9 R/W-0 TXEN R/W-0 SYNC U-0 -- R/W-0 BRGH R-1 TRMT R/W-0 TX9D bit 0
CSRC: Clock Source Select bit Asynchronous mode: Don't care Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) TX9: 9-bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled Note: SREN/CREN overrides TXEN in SYNC mode. SYNC: USART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode Unimplemented: Read as '0' BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full TX9D: 9th bit of Transmit Data Can be Address/Data bit or a parity bit. Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3 bit 2
bit 1
bit 0
DS39564B-page 166
2002 Microchip Technology Inc.
PIC18FXX2
REGISTER 16-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER
R/W-0 SPEN bit 7 bit 7 R/W-0 RX9 R/W-0 SREN R/W-0 CREN R/W-0 ADDEN R-0 FERR R-0 OERR R-x RX9D bit 0
SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins) 0 = Serial port disabled RX9: 9-bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception SREN: Single Receive Enable bit Asynchronous mode: Don't care Synchronous mode - Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - Slave: Don't care CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN) 0 = Disables continuous receive ADDEN: Address Detect Enable bit Asynchronous mode 9-bit (RX9 = 1): 1 = Enables address detection, enable interrupt and load of the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received, and ninth bit can be used as parity bit FERR: Framing Error bit 1 = Framing error (can be updated by reading RCREG register and receive next valid byte) 0 = No framing error OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit CREN) 0 = No overrun error RX9D: 9th bit of Received Data This can be Address/Data bit or a parity bit, and must be calculated by user firmware. Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
2002 Microchip Technology Inc.
DS39564B-page 167
PIC18FXX2
16.1 USART Baud Rate Generator (BRG)
Example 16-1 shows the calculation of the baud rate error for the following conditions: * * * * FOSC = 16 MHz Desired Baud Rate = 9600 BRGH = 0 SYNC = 0
The BRG supports both the Asynchronous and Synchronous modes of the USART. It is a dedicated 8-bit baud rate generator. The SPBRG register controls the period of a free running 8-bit timer. In Asynchronous mode, bit BRGH (TXSTA<2>) also controls the baud rate. In Synchronous mode, bit BRGH is ignored. Table 16-1 shows the formula for computation of the baud rate for different USART modes, which only apply in Master mode (internal clock). Given the desired baud rate and Fosc, the nearest integer value for the SPBRG register can be calculated using the formula in Table 16-1. From this, the error in baud rate can be determined.
It may be advantageous to use the high baud rate (BRGH = 1) even for slower baud clocks. This is because the FOSC/(16(X + 1)) equation can reduce the baud rate error in some cases. Writing a new value to the SPBRG register causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate.
16.1.1
SAMPLING
The data on the RC7/RX/DT pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX pin.
EXAMPLE 16-1:
Desired Baud Rate Solving for X: X X X Calculated Baud Rate Error
CALCULATING BAUD RATE ERROR
= FOSC / (64 (X + 1)) = ( (FOSC / Desired Baud Rate) / 64 ) - 1 = ((16000000 / 9600) / 64) - 1 = [25.042] = 25 = = = = = 16000000 / (64 (25 + 1)) 9615 (Calculated Baud Rate - Desired Baud Rate) Desired Baud Rate (9615 - 9600) / 9600 0.16%
TABLE 16-1:
SYNC
BAUD RATE FORMULA
BRGH = 0 (Low Speed) BRGH = 1 (High Speed) Baud Rate = FOSC/(16(X+1)) N/A
0 (Asynchronous) Baud Rate = FOSC/(64(X+1)) (Synchronous) Baud Rate = FOSC/(4(X+1)) 1 Legend: X = value in SPBRG (0 to 255)
TABLE 16-2:
Name TXSTA RCSTA SPBRG
REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Bit 6 TX9 RX9 Bit 5 TXEN SREN Bit 4 SYNC CREN Bit 3 -- ADDEN Bit 2 BRGH FERR Bit 1 TRMT OERR Bit 0 TX9D RX9D Value on POR, BOR 0000 -010 0000 -00x 0000 0000 Value on All Other RESETS 0000 -010 0000 -00x 0000 0000
Bit 7 CSRC SPEN
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used by the BRG.
DS39564B-page 168
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 16-3:
BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW
BAUD RATES FOR SYNCHRONOUS MODE
SPBRG value (decimal) 129 103 32 19 0 255 SPBRG value (decimal) 207 51 41 12 7 0 255 SPBRG value (decimal) 103 51 12 9 2 1 0 255 33 MHz KBAUD NA NA NA NA NA 77.10 95.93 294.64 485.30 8250 32.23 10 MHz KBAUD NA NA NA NA 19.23 75.76 96.15 312.50 500 2500 9.77 % ERROR +0.16 -1.36 +0.16 +4.17 0 % ERROR +0.39 -0.07 -1.79 -2.94 SPBRG value (decimal) 106 85 27 16 0 255 SPBRG value (decimal) 129 32 25 7 4 0 255 SPBRG value (decimal) 92 46 11 8 2 1 0 255 25 MHz KBAUD NA NA NA NA NA 77.16 96.15 297.62 480.77 6250 24.41 % ERROR +0.47 +0.16 -0.79 -3.85 SPBRG value (decimal) 80 64 20 12 0 255 SPBRG value (decimal) 185 92 22 18 5 3 0 255 SPBRG value (decimal) 207 103 25 12 2 2 0 0 255 20 MHz KBAUD NA NA NA NA NA 76.92 96.15 294.12 500 5000 19.53 % ERROR +0.16 +0.16 -1.96 0 SPBRG value (decimal) 64 51 16 9 0 255 SPBRG value (decimal) 131 65 16 12 3 2 0 255 SPBRG value (decimal) 26 6 2 0 0 255
FOSC = 40 MHz KBAUD NA NA NA NA NA 76.92 96.15 303.03 500 10000 39.06 % ERROR +0.16 +0.16 +1.01 0 -
FOSC = 16 MHz KBAUD NA NA NA NA 19.23 76.92 95.24 307.70 500 4000 15.63 % ERROR +0.16 +0.16 -0.79 +2.56 0 -
7.15909 MHz KBAUD NA NA NA 9.62 19.24 77.82 94.20 298.35 447.44 1789.80 6.99 1 MHz KBAUD NA 1.20 2.40 9.62 19.23 83.33 83.33 250 NA 250 0.98 % ERROR +0.16 +0.16 +0.16 +0.16 +8.51 -13.19 -16.67 % ERROR +0.23 +0.23 +1.32 -1.88 -0.57 -10.51 -
5.0688 MHz KBAUD NA NA NA 9.60 19.20 74.54 97.48 316.80 422.40 1267.20 4.95 % ERROR 0 0 -2.94 +1.54 +5.60 -15.52 -
FOSC = 4 MHz KBAUD NA NA NA 9.62 19.23 76.92 1000 333.33 500 1000 3.91 % ERROR +0.16 +0.16 +0.16 +4.17 +11.11 0 -
3.579545 MHz KBAUD NA NA NA 9.62 19.04 74.57 99.43 298.30 447.44 894.89 3.50 % ERROR +0.23 -0.83 -2.90 +3.57 -0.57 -10.51 -
32.768 kHz KBAUD 0.30 1.17 2.73 8.20 NA NA NA NA NA 8.20 0.03 % ERROR +1.14 -2.48 +13.78 -14.67 -
2002 Microchip Technology Inc.
DS39564B-page 169
PIC18FXX2
TABLE 16-4:
BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW
BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0)
SPBRG value (decimal) 64 32 7 6 1 0 0 255 SPBRG value (decimal) 207 103 25 12 2 2 0 0 255 SPBRG value (decimal) 207 51 25 6 2 0 0 255 33 MHz KBAUD NA NA 2.40 9.55 19.10 73.66 103.13 257.81 NA 515.63 2.01 10 MHz KBAUD NA 1.20 2.40 9.77 19.53 78.13 78.13 156.25 NA 156.25 0.61 % ERROR +0.16 +0.16 +1.73 +1.73 +1.73 -18.62 -47.92 % ERROR -0.07 -0.54 -0.54 -4.09 +7.42 -14.06 SPBRG value (decimal) 214 53 26 6 4 1 0 255 SPBRG value (decimal) 129 64 15 7 1 1 0 0 255 SPBRG value (decimal) 185 46 22 5 2 0 0 255 25 MHz KBAUD NA NA 2.40 9.53 19.53 78.13 97.66 NA NA 390.63 1.53 % ERROR -0.15 -0.76 +1.73 +1.73 +1.73 SPBRG value (decimal) 162 40 19 4 3 0 255 SPBRG value (decimal) 92 46 11 5 0 0 255 SPBRG value (decimal) 51 12 6 1 0 0 255 20 MHz KBAUD NA NA 2.40 9.47 19.53 78.13 104.17 312.50 NA 312.50 1.22 % ERROR +0.16 -1.36 +1.73 +1.73 +8.51 +4.17 SPBRG value (decimal) 129 32 15 3 2 0 0 255 SPBRG value (decimal) 65 32 7 3 0 0 255 SPBRG value (decimal) 1 0 255
FOSC = 40 MHz KBAUD NA NA NA 9.62 18.94 78.13 89.29 312.50 625 625 2.44 % ERROR +0.16 -1.36 +1.73 -6.99 +4.17 +25.00 -
FOSC = 16 MHz KBAUD NA 1.20 2.40 9.62 19.23 83.33 83.33 250 NA 250 0.98 % ERROR +0.16 +0.16 +0.16 +0.16 +8.51 -13.19 -16.67 -
7.15909 MHz KBAUD NA 1.20 2.38 9.32 18.64 111.86 NA NA NA 111.86 0.44 1 MHz KBAUD 0.30 1.20 2.23 7.81 15.63 NA NA NA NA 15.63 0.06 % ERROR +0.16 +0.16 -6.99 -18.62 -18.62 % ERROR +0.23 -0.83 -2.90 -2.90 +45.65 -
5.0688 MHz KBAUD NA 1.20 2.40 9.90 19.80 79.20 NA NA NA 79.20 0.31 % ERROR 0 0 +3.13 +3.13 +3.13 -
FOSC = 4 MHz KBAUD 0.30 1.20 2.40 8.93 20.83 62.50 NA NA NA 62.50 0.24 % ERROR -0.16 +1.67 +1.67 -6.99 +8.51 -18.62 -
3.579545 MHz KBAUD 0.30 1.19 2.43 9.32 18.64 55.93 NA NA NA 55.93 0.22 % ERROR +0.23 -0.83 +1.32 -2.90 -2.90 -27.17 -
32.768 kHz KBAUD 0.26 NA NA NA NA NA NA NA NA 0.51 0.002 % ERROR -14.67 -
DS39564B-page 170
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 16-5:
BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (Kbps) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW
BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1)
SPBRG value (decimal) 129 32 25 7 4 0 255 SPBRG value (decimal) 103 51 12 9 2 1 0 255 SPBRG value (decimal) 207 103 25 12 0 255 33 MHz KBAUD NA NA NA 9.60 19.28 76.39 98.21 294.64 515.63 2062.50 8,06 10 MHz KBAUD NA NA NA 9.62 18.94 78.13 89.29 312.50 625 625 2.44 % ERROR +0.16 -1.36 +1.73 -6.99 +4.17 +25.00 % ERROR -0.07 +0.39 -0.54 +2.31 -1.79 +3.13 SPBRG value (decimal) 214 106 26 20 6 3 0 255 SPBRG value (decimal) 64 32 7 6 1 0 0 255 SPBRG value (decimal) 185 92 22 11 2 1 0 0 255 25 MHz KBAUD NA NA NA 9.59 19.30 78.13 97.66 312.50 520.83 1562.50 6.10 % ERROR -0.15 +0.47 +1.73 +1.73 +4.17 +4.17 SPBRG value (decimal) 162 80 19 15 4 2 0 255 SPBRG value (decimal) 185 46 22 5 4 0 0 0 255 SPBRG value (decimal) 207 51 25 6 2 0 0 255 20 MHz KBAUD NA NA NA 9.62 19.23 78.13 96.15 312.50 416.67 1250 4.88 % ERROR +0.16 +0.16 +1.73 +0.16 +4.17 -16.67 SPBRG value (decimal) 129 64 15 12 3 2 0 255 SPBRG value (decimal) 131 32 16 3 2 0 0 255 SPBRG value (decimal) 6 1 0 0 255
FOSC = 40 MHz KBAUD NA NA NA NA 19.23 75.76 96.15 312.50 500 2500 9.77 % ERROR +0.16 -1.36 +0.16 +4.17 0 -
FOSC = 16 MHz KBAUD NA NA NA 9.62 19.23 76.92 100 333.33 500 1000 3.91 % ERROR +0.16 +0.16 +0.16 +4.17 +11.11 0 -
7.15909 MHz KBAUD NA NA 2.41 9.52 19.45 74.57 89.49 447.44 447.44 447.44 1.75 1 MHz KBAUD 0.30 1.20 2.40 8.93 20.83 62.50 NA NA NA 62.50 0.24 % ERROR +0.16 +0.16 +0.16 -6.99 +8.51 -18.62 % ERROR +0.23 -0.83 +1.32 -2.90 -6.78 +49.15 -10.51 -
5.0688 MHz KBAUD NA NA 2.40 9.60 18.64 79.20 105.60 316.80 NA 316.80 1.24 % ERROR 0 0 -2.94 +3.13 +10.00 +5.60 -
FOSC = 4 MHz KBAUD NA 1.20 2.40 9.62 19.23 NA NA NA NA 250 0.98 % ERROR +0.16 +0.16 +0.16 +0.16 -
3.579545 MHz KBAUD NA 1.20 2.41 9.73 18.64 74.57 111.86 223.72 NA 55.93 0.22 % ERROR +0.23 +0.23 +1.32 -2.90 -2.90 +16.52 -25.43 -
32.768 kHz KBAUD 0.29 1.02 2.05 NA NA NA NA NA NA 2.05 0.008 % ERROR -2.48 -14.67 -14.67 -
2002 Microchip Technology Inc.
DS39564B-page 171
PIC18FXX2
16.2 USART Asynchronous Mode
In this mode, the USART uses standard non-return-tozero (NRZ) format (one START bit, eight or nine data bits and one STOP bit). The most common data format is 8-bits. An on-chip dedicated 8-bit baud rate generator can be used to derive standard baud rate frequencies from the oscillator. The USART transmits and receives the LSb first. The USART's transmitter and receiver are functionally independent, but use the same data format and baud rate. The baud rate generator produces a clock, either x16 or x64 of the bit shift rate, depending on bit BRGH (TXSTA<2>). Parity is not supported by the hardware, but can be implemented in software (and stored as the ninth data bit). Asynchronous mode is stopped during SLEEP. Asynchronous mode is selected by clearing bit SYNC (TXSTA<4>). The USART Asynchronous module consists of the following important elements: * * * * Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver flag bit TXIF (PIR1<4>) is set. This interrupt can be enabled/disabled by setting/clearing enable bit TXIE ( PIE1<4>). Flag bit TXIF will be set, regardless of the state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit TXIF indicated the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. Status bit TRMT is a read-only bit, which is set when the TSR register is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. Note 1: The TSR register is not mapped in data memory, so it is not available to the user. 2: Flag bit TXIF is set when enable bit TXEN is set. To set up an asynchronous transmission: 1. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH (Section 16.1). Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. If interrupts are desired, set enable bit TXIE. If 9-bit transmission is desired, set transmit bit TX9. Can be used as address/data bit. Enable the transmission by setting bit TXEN, which will also set bit TXIF. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. Load data to the TXREG register (starts transmission). Note: TXIF is not cleared immediately upon loading data into the transmit buffer TXREG. The flag bit becomes valid in the second instruction cycle following the load instruction.
2. 3. 4. 5. 6. 7.
16.2.1
USART ASYNCHRONOUS TRANSMITTER
The USART transmitter block diagram is shown in Figure 16-1. The heart of the transmitter is the Transmit (serial) Shift Register (TSR). The shift register obtains its data from the read/write transmit buffer, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the STOP bit has been transmitted from the previous load. As soon as the STOP bit is transmitted, the TSR is loaded with new data from the TXREG register (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCY), the TXREG register is empty and
FIGURE 16-1:
USART TRANSMIT BLOCK DIAGRAM
Data Bus TXIF TXREG Register 8 MSb (8) Interrupt TXEN Baud Rate CLK TRMT SPBRG Baud Rate Generator TX9 TX9D SPEN
***
TXIE
LSb 0 Pin Buffer and Control RC6/TX/CK pin
TSR Register
DS39564B-page 172
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 16-2:
Write to TXREG BRG Output (Shift Clock) RC6/TX/CK (pin) TXIF bit (Transmit Buffer Reg. Empty Flag) Word 1
ASYNCHRONOUS TRANSMISSION
START bit
bit 0
bit 1 Word 1
bit 7/8
STOP bit
TRMT bit (Transmit Shift Reg. Empty Flag)
Word 1 Transmit Shift Reg
FIGURE 16-3:
Write to TXREG BRG Output (Shift Clock) RC6/TX/CK (pin) TXIF bit (Interrupt Reg. Flag)
ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
Word 1 Word 2
START bit
bit 0
bit 1 Word 1
bit 7/8
STOP bit
START bit Word 2
bit 0
TRMT bit (Transmit Shift Reg. Empty Flag) Note:
Word 1 Transmit Shift Reg.
Word 2 Transmit Shift Reg.
This timing diagram shows two consecutive transmissions.
TABLE 16-6:
Name
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 6 Bit 5 Bit 4 Bit 3 RBIE Bit 2 Bit 1 Bit 0 RBIF Value on POR, BOR Value on All Other RESETS
Bit 7
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE PIR1 PIE1 IPR1 RCSTA TXREG TXSTA PSPIF(1) PSPIE(1) PSPIP(1) SPEN CSRC ADIF ADIE ADIP RX9 TX9 RCIF RCIE RCIP SREN TXEN TXIF TXIE TXIP
TMR0IF INT0IF
0000 000x 0000 000u
SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 FERR BRGH OERR TRMT RX9D TX9D 0000 -00x 0000 -00x 0000 0000 0000 0000 0000 -010 0000 -010 0000 0000 0000 0000
CREN ADDEN SYNC --
USART Transmit Register
SPBRG Baud Rate Generator Register
Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Transmission. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
2002 Microchip Technology Inc.
DS39564B-page 173
PIC18FXX2
16.2.2 USART ASYNCHRONOUS RECEIVER 16.2.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT
The receiver block diagram is shown in Figure 16-4. The data is received on the RC7/RX/DT pin and drives the data recovery block. The data recovery block is actually a high speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. To set up an Asynchronous Reception: Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH (Section 16.1). 2. Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. 3. If interrupts are desired, set enable bit RCIE. 4. If 9-bit reception is desired, set bit RX9. 5. Enable the reception by setting bit CREN. 6. Flag bit RCIF will be set when reception is complete and an interrupt will be generated if enable bit RCIE was set. 7. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG register. 9. If any error occurred, clear the error by clearing enable bit CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 1.
This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is required, set the BRGH bit. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RCIP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RCIF bit will be set when reception is complete. The interrupt will be acknowledged if the RCIE and GIE bits are set. 8. Read the RCSTA register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU.
FIGURE 16-4:
USART RECEIVE BLOCK DIAGRAM
CREN x64 Baud Rate CLK
/ 64 or / 16
OERR
FERR
SPBRG
MSb STOP (8) 7
RSR Register
***
LSb 0 START
1
Baud Rate Generator RX9 RC7/RX/DT Pin Buffer and Control Data Recovery RX9D RCREG Register FIFO SPEN 8 Interrupt RCIF RCIE Data Bus
DS39564B-page 174
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 16-5:
RX (pin) Rcv Shift Reg Rcv Buffer Reg Read Rcv Buffer Reg RCREG RCIF (Interrupt Flag) OERR bit CREN Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing the OERR (overrun) bit to be set.
ASYNCHRONOUS RECEPTION
START bit bit0 bit1 bit7/8 STOP bit START bit0 bit bit7/8 STOP bit START bit bit7/8 STOP bit
Word 1 RCREG
Word 2 RCREG
TABLE 16-7:
Name INTCON PIR1 PIE1 IPR1 RCSTA RCREG TXSTA SPBRG
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Bit 6 PEIE/ GIEL ADIF ADIE ADIP RX9 TX9 Bit 5 Bit 4 Bit 3 RBIE Bit 2 Bit 1 Bit 0 RBIF Value on POR, BOR 0000 000x Value on All Other RESETS 0000 000u 0000 0000 0000 0000 0000 0000 0000 -00x 0000 0000 0000 -010 0000 0000
Bit 7 GIE/GIEH PSPIF(1) PSPIE(1) PSPIP(1) SPEN CSRC
TMR0IE INT0IE RCIF RCIE RCIP SREN TXEN TXIF TXIE TXIP
TMR0IF INT0IF
SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 OERR TRMT RX9D TX9D 0000 -00x 0000 0000 0000 -010 0000 0000
CREN ADDEN FERR SYNC -- BRGH
USART Receive Register Baud Rate Generator Register
Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Reception. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
2002 Microchip Technology Inc.
DS39564B-page 175
PIC18FXX2
16.3 USART Synchronous Master Mode
(PIE1<4>). Flag bit TXIF will be set, regardless of the state of enable bit TXIE, and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit TXIF indicates the status of the TXREG register, another bit TRMT (TXSTA<1>) shows the status of the TSR register. TRMT is a read only bit, which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory, so it is not available to the user. To set up a Synchronous Master Transmission: 1. 2. 3. 4. 5. 6. 7. Initialize the SPBRG register for the appropriate baud rate (Section 16.1). Enable the synchronous master serial port by setting bits SYNC, SPEN, and CSRC. If interrupts are desired, set enable bit TXIE. If 9-bit transmission is desired, set bit TX9. Enable the transmission by setting bit TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. Start transmission by loading data to the TXREG register. Note: TXIF is not cleared immediately upon loading data into the transmit buffer TXREG. The flag bit becomes valid in the second instruction cycle following the load instruction.
In Synchronous Master mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit SYNC (TXSTA<4>). In addition, enable bit SPEN (RCSTA<7>) is set in order to configure the RC6/TX/CK and RC7/RX/DT I/O pins to CK (clock) and DT (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK line. The Master mode is entered by setting bit CSRC (TXSTA<7>).
16.3.1
USART SYNCHRONOUS MASTER TRANSMISSION
The USART transmitter block diagram is shown in Figure 16-1. The heart of the transmitter is the Transmit (serial) Shift Register (TSR). The shift register obtains its data from the read/write transmit buffer register TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG is empty and interrupt bit TXIF (PIR1<4>) is set. The interrupt can be enabled/disabled by setting/clearing enable bit TXIE
TABLE 16-8:
Name INTCON PIR1 PIE1 IPR1 RCSTA TXREG TXSTA SPBRG Bit 7
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Bit 6 PEIE/ GIEL ADIF ADIE ADIP RX9 TX9 Bit 5 Bit 4 Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF Bit 1 INT0IF Bit 0 RBIF TMR1IF Value on POR, BOR 0000 000x 0000 0000 0000 0000 0000 0000 0000 -00x 0000 0000 SYNC -- BRGH TRMT TX9D 0000 -010 0000 0000 Value on All Other RESETS 0000 000u 0000 0000 0000 0000 0000 0000 0000 -00x 0000 0000 0000 -010 0000 0000
GIE/ GIEH PSPIF(1) PSPIE(1) PSPIP(1) SPEN CSRC
TMR0IE INT0IE RCIF RCIE RCIP SREN TXEN TXIF TXIE TXIP
CCP1IF TMR2IF
CCP1IE TMR2IE TMR1IE CCP1IP TMR2IP TMR1IP FERR OERR RX9D
CREN ADDEN
USART Transmit Register Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Transmission. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
DS39564B-page 176
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 16-6: SYNCHRONOUS TRANSMISSION
Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX/DT pin RC6/TX/CK pin Write to TXREG Reg TXIF bit (Interrupt Flag) TRMT bit TRMT '1'
bit 0
bit 1 Word 1
bit 2
bit 7
bit 0
bit 1 Word 2
bit 7
Write Word1
Write Word2
TXEN bit Note:
'1'
Sync Master mode; SPBRG = '0'. Continuous transmission of two 8-bit words.
FIGURE 16-7:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
bit0 bit1 bit2 bit6 bit7
RC7/RX/DT pin RC6/TX/CK pin
Write to TXREG reg
TXIF bit
TRMT bit
TXEN bit
2002 Microchip Technology Inc.
DS39564B-page 177
PIC18FXX2
16.3.2 USART SYNCHRONOUS MASTER RECEPTION
If interrupts are desired, set enable bit RCIE. If 9-bit reception is desired, set bit RX9. If a single reception is required, set bit SREN. For continuous reception, set bit CREN. 7. Interrupt flag bit RCIF will be set when reception is complete and an interrupt will be generated if the enable bit RCIE was set. 8. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG register. 10. If any error occurred, clear the error by clearing bit CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 4. 5. 6.
Once Synchronous mode is selected, reception is enabled by setting either enable bit SREN (RCSTA<5>), or enable bit CREN (RCSTA<4>). Data is sampled on the RC7/RX/DT pin on the falling edge of the clock. If enable bit SREN is set, only a single word is received. If enable bit CREN is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. 2. 3. Initialize the SPBRG register for the appropriate baud rate (Section 16.1). Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. Ensure bits CREN and SREN are clear.
TABLE 16-9:
Name INTCON PIR1 PIE1 IPR1 RCSTA RCREG TXSTA SPBRG
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Bit 6 PEIE/ GIEL ADIF ADIE ADIP RX9 TX9 Bit 5 Bit 4 Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN -- Bit 2 TMR0IF Bit 1 INT0IF Bit 0 RBIF Value on POR, BOR Value on All Other RESETS
Bit 7 GIE/ GIEH PSPIF(1) PSPIE(1) PSPIP(1) SPEN CSRC
TMR0IE INT0IE RCIF RCIE RCIP SREN TXEN TXIF TXIE TXIP CREN SYNC
0000 000x 0000 000u
CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 FERR BRGH OERR TRMT RX9D TX9D 0000 -00x 0000 -00x 0000 0000 0000 0000 0000 -010 0000 -010 0000 0000 0000 0000
USART Receive Register Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Reception. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
FIGURE 16-8:
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX/DT pin RC6/TX/CK pin Write to bit SREN SREN bit CREN bit RCIF bit '0'
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
'0'
(Interrupt)
Read RXREG Note: Timing diagram demonstrates Sync Master mode with bit SREN = '1' and bit BRGH = '0'.
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PIC18FXX2
16.4 USART Synchronous Slave Mode
To set up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting bits SYNC and SPEN and clearing bit CSRC. Clear bits CREN and SREN. If interrupts are desired, set enable bit TXIE. If 9-bit transmission is desired, set bit TX9. Enable the transmission by setting enable bit TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. Start transmission by loading data to the TXREG register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. Synchronous Slave mode differs from the Master mode in the fact that the shift clock is supplied externally at the RC6/TX/CK pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in SLEEP mode. Slave mode is entered by clearing bit CSRC (TXSTA<7>).
16.4.1
USART SYNCHRONOUS SLAVE TRANSMIT
2. 3. 4. 5. 6. 7. 8.
The operation of the Synchronous Master and Slave modes are identical, except in the case of the SLEEP mode. If two words are written to the TXREG and then the SLEEP instruction is executed, the following will occur: a) b) c) d) The first word will immediately transfer to the TSR register and transmit. The second word will remain in TXREG register. Flag bit TXIF will not be set. When the first word has been shifted out of TSR, the TXREG register will transfer the second word to the TSR and flag bit TXIF will now be set. If enable bit TXIE is set, the interrupt will wake the chip from SLEEP. If the global interrupt is enabled, the program will branch to the interrupt vector.
e)
TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Name INTCON PIR1 PIE1 IPR1 RCSTA TXREG TXSTA SPBRG Bit 7 GIE/ GIEH PSPIF(1) PSPIE(1) PSPIP(1) SPEN CSRC Bit 6 PEIE/ GIEL ADIF ADIE ADIP RX9 TX9 Bit 5 Bit 4 Bit 3 RBIE SSPIF SSPIE SSPIP Bit 2 TMR0IF Bit 1 INT0IF Bit 0 RBIF Value on POR, BOR Value on All Other RESETS
TMR0IE INT0IE RCIF RCIE RCIP SREN TXEN TXIF TXIE TXIP
0000 000x 0000 000u
CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 FERR BRGH OERR TRMT RX9D TX9D 0000 -00x 0000 -00x 0000 0000 0000 0000 0000 -010 0000 -010 0000 0000 0000 0000
CREN ADDEN SYNC --
USART Transmit Register Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Slave Transmission. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
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PIC18FXX2
16.4.2 USART SYNCHRONOUS SLAVE RECEPTION
To set up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting bits SYNC and SPEN and clearing bit CSRC. If interrupts are desired, set enable bit RCIE. If 9-bit reception is desired, set bit RX9. To enable reception, set enable bit CREN. Flag bit RCIF will be set when reception is complete. An interrupt will be generated if enable bit RCIE was set. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading the RCREG register. If any error occurred, clear the error by clearing bit CREN. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set.
The operation of the Synchronous Master and Slave modes is identical, except in the case of the SLEEP mode and bit SREN, which is a "don't care" in Slave mode. If receive is enabled by setting bit CREN prior to the SLEEP instruction, then a word may be received during SLEEP. On completely receiving the word, the RSR register will transfer the data to the RCREG register, and if enable bit RCIE bit is set, the interrupt generated will wake the chip from SLEEP. If the global interrupt is enabled, the program will branch to the interrupt vector.
2. 3. 4. 5.
6.
7. 8. 9.
TABLE 16-11: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name INTCON PIR1 PIE1 IPR1 RCSTA RCREG TXSTA SPBRG Bit 7 GIE/ GIEH PSPIF(1) PSPIE(1) PSPIP(1) SPEN CSRC Bit 6 PEIE/ GIEL ADIF ADIE ADIP RX9 TX9 Bit 5 Bit 4 Bit 3 RBIE SSPIF SSPIE SSPIP ADDEN -- Bit 2 Bit 1 Bit 0 RBIF Value on POR, BOR Value on All Other RESETS
TMR0IE INT0IE RCIF RCIE RCIP SREN TXEN TXIF TXIE TXIP CREN SYNC
TMR0IF INT0IF
0000 000x 0000 000u
CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000 FERR BRGH OERR TRMT RX9D TX9D 0000 -00x 0000 -00x 0000 0000 0000 0000 0000 -010 0000 -010 0000 0000 0000 0000
USART Receive Register Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Slave Reception. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
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PIC18FXX2
17.0 COMPATIBLE 10-BIT ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE
The A/D module has four registers. These registers are: * * * * A/D Result High Register (ADRESH) A/D Result Low Register (ADRESL) A/D Control Register 0 (ADCON0) A/D Control Register 1 (ADCON1)
The Analog-to-Digital (A/D) converter module has five inputs for the PIC18F2X2 devices and eight for the PIC18F4X2 devices. This module has the ADCON0 and ADCON1 register definitions that are compatible with the mid-range A/D module. The A/D allows conversion of an analog input signal to a corresponding 10-bit digital number.
The ADCON0 register, shown in Register 17-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 17-2, configures the functions of the port pins.
REGISTER 17-1:
ADCON0 REGISTER
R/W-0 ADCS1 bit 7 R/W-0 ADCS0 R/W-0 CHS2 R/W-0 CHS1 R/W-0 CHS0 R/W-0 GO/DONE U-0 -- R/W-0 ADON bit 0
bit 7-6
ADCS1:ADCS0: A/D Conversion Clock Select bits (ADCON0 bits in bold)
ADCON1
0 0 0 0 1 1 1 1
ADCON0
00 01 10 11 00 01 10 11
Clock Conversion FOSC/2 FOSC/8 FOSC/32 FRC (clock derived from the internal A/D RC oscillator) FOSC/4 FOSC/16 FOSC/64 FRC (clock derived from the internal A/D RC oscillator)
bit 5-3
CHS2:CHS0: Analog Channel Select bits 000 = channel 0, (AN0) 001 = channel 1, (AN1) 010 = channel 2, (AN2) 011 = channel 3, (AN3) 100 = channel 4, (AN4) 101 = channel 5, (AN5) 110 = channel 6, (AN6) 111 = channel 7, (AN7) Note: The PIC18F2X2 devices do not implement the full 8 A/D channels; the unimplemented selections are reserved. Do not select any unimplemented channel.
bit 2
GO/DONE: A/D Conversion Status bit When ADON = 1: 1 = A/D conversion in progress (setting this bit starts the A/D conversion which is automatically cleared by hardware when the A/D conversion is complete) 0 = A/D conversion not in progress Unimplemented: Read as '0' ADON: A/D On bit 1 = A/D converter module is powered up 0 = A/D converter module is shut-off and consumes no operating current Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 1 bit 0
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PIC18FXX2
REGISTER 17-2: ADCON1 REGISTER
R/W-0 ADFM bit 7 bit 7 ADFM: A/D Result Format Select bit 1 = Right justified. Six (6) Most Significant bits of ADRESH are read as '0'. 0 = Left justified. Six (6) Least Significant bits of ADRESL are read as '0'. ADCS2: A/D Conversion Clock Select bit (ADCON1 bits in bold) ADCON1 ADCON0
0 0 0 0 1 1 1 1 00 01 10 11 00 01 10 11
R/W-0 ADCS2
U-0 --
U-0 --
R/W-0 PCFG3
R/W-0 PCFG2
R/W-0 PCFG1
R/W-0 PCFG0 bit 0
bit 6
Clock Conversion
FOSC/2 FOSC/8 FOSC/32 FRC (clock derived from the internal A/D RC oscillator) FOSC/4 FOSC/16 FOSC/64 FRC (clock derived from the internal A/D RC oscillator)
bit 5-4 bit 3-0
Unimplemented: Read as '0' PCFG3:PCFG0: A/D Port Configuration Control bits
PCFG <3:0>
0000 0001 0010 0011 0100 0101 011x 1000 1001 1010 1011 1100 1101 1110 1111
AN7 A A D D D D D A D D D D D D D
AN6 A A D D D D D A D D D D D D D
AN5 A A D D D D D A A A A D D D D
AN4 A A A A D D D A A A A A D D D
AN3 A VREF+ A VREF+ A VREF+ D VREF+ A VREF+ VREF+ VREF+ VREF+ D VREF+
AN2 A A A A D D D VREFA A VREFVREFVREFD VREF-
AN1 A A A A A A D A A A A A A D D
AN0 A A A A A A D A A A A A A A A
VREF+ VDD AN3 VDD AN3 VDD AN3 -- AN3 VDD AN3 AN3 AN3 AN3 VDD AN3
VREFVSS VSS VSS VSS VSS VSS -- AN2 VSS VSS AN2 AN2 AN2 VSS AN2
C/R 8/0 7/1 5/0 4/1 3/0 2/1 0/0 6/2 6/0 5/1 4/2 3/2 2/2 1/0 1/2
A = Analog input D = Digital I/O C/R = # of analog input channels / # of A/D voltage references Legend: R = Readable bit - n = Value at POR Note: W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
On any device RESET, the port pins that are multiplexed with analog functions (ANx) are forced to be an analog input.
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PIC18FXX2
The analog reference voltage is software selectable to either the device's positive and negative supply voltage (VDD and VSS), or the voltage level on the RA3/AN3/ VREF+ pin and RA2/AN2/VREF- pin. The A/D converter has a unique feature of being able to operate while the device is in SLEEP mode. To operate in SLEEP, the A/D conversion clock must be derived from the A/D's internal RC oscillator. The output of the sample and hold is the input into the converter, which generates the result via successive approximation. A device RESET forces all registers to their RESET state. This forces the A/D module to be turned off and any conversion is aborted. Each port pin associated with the A/D converter can be configured as an analog input (RA3 can also be a voltage reference) or as a digital I/O. The ADRESH and ADRESL registers contain the result of the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH/ ADRESL registers, the GO/DONE bit (ADCON0<2>) is cleared, and A/D interrupt flag bit, ADIF is set. The block diagram of the A/D module is shown in Figure 17-1.
FIGURE 17-1:
A/D BLOCK DIAGRAM
CHS<2:0>
111 110 101 100 VAIN (Input Voltage) 10-bit Converter A/D PCFG<3:0> VDD VREF+ Reference Voltage VREFVSS * These channels are implemented only on the PIC18F4X2 devices. 011 010 001 000
AN7* AN6* AN5* AN4 AN3 AN2 AN1 AN0
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PIC18FXX2
The value that is in the ADRESH/ADRESL registers is not modified for a Power-on Reset. The ADRESH/ ADRESL registers will contain unknown data after a Power-on Reset. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as an input. To determine acquisition time, see Section 17.1. After this acquisition time has elapsed, the A/D conversion can be started. The following steps should be followed for doing an A/D conversion: 1. Configure the A/D module: * Configure analog pins, voltage reference and digital I/O (ADCON1) * Select A/D input channel (ADCON0) * Select A/D conversion clock (ADCON0) * Turn on A/D module (ADCON0) Configure A/D interrupt (if desired): * Clear ADIF bit * Set ADIE bit * Set GIE bit * Set PEIE bit Wait the required acquisition time. Start conversion: * Set GO/DONE bit (ADCON0) 5. Wait for A/D conversion to complete, by either: * Polling for the GO/DONE bit to be cleared (interrupts disabled) OR 6. 7. * Waiting for the A/D interrupt Read A/D Result registers (ADRESH/ADRESL); clear bit ADIF if required. For next conversion, go to step 1 or step 2 as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2 TAD is required before the next acquisition starts.
17.1
A/D Acquisition Requirements
2.
3. 4.
For the A/D converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 17-2. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD). The source impedance affects the offset voltage at the analog input (due to pin leakage current). The maximum recommended impedance for analog sources is 2.5 k. After the analog input channel is selected (changed), this acquisition must be done before the conversion can be started. Note: When the conversion is started, the holding capacitor is disconnected from the input pin.
FIGURE 17-2:
ANALOG INPUT MODEL
VDD VT = 0.6V Sampling Switch RIC 1k SS RSS
Rs
ANx
VAIN
CPIN 5 pF VT = 0.6V
I LEAKAGE 500 nA
CHOLD = 120 pF
VSS
Legend: CPIN = input capacitance VT = threshold voltage I LEAKAGE = leakage current at the pin due to various junctions RIC SS CHOLD = interconnect resistance = sampling switch = sample/hold capacitance (from DAC)
6V 5V VDD 4V 3V 2V
5 6 7 8 9 10 11 Sampling Switch (k)
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PIC18FXX2
To calculate the minimum acquisition time, Equation 17-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution.
EQUATION 17-1:
TACQ = =
ACQUISITION TIME
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient TAMP + TC + TCOFF
EQUATION 17-2:
VHOLD = or = TC
A/D MINIMUM CHARGING TIME
(VREF - (VREF/2048)) * (1 - e(-Tc/CHOLD(RIC + RSS + RS))) -(120 pF)(1 k + RSS + RS) ln(1/2048)
Example 17-1 shows the calculation of the minimum required acquisition time, TACQ. This calculation is based on the following application system assumptions: * * * * * * CHOLD Rs Conversion Error VDD Temperature VHOLD = = = = = 120 pF 2.5 k 1/2 LSb 5V Rss = 7 k 50C (system max.) 0V @ time = 0
EXAMPLE 17-1:
TACQ = TACQ = TC =
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
TAMP + TC + TCOFF 2 s + TC + [(Temp - 25C)(0.05 s/C)] -CHOLD (RIC + RSS + RS) ln(1/2048) -120 pF (1 k + 7 k + 2.5 k) ln(0.0004883) -120 pF (10.5 k) ln(0.0004883) -1.26 s (-7.6246) 9.61 s 2 s + 9.61 s + [(50C - 25C)(0.05 s/C)] 11.61 s + 1.25 s 12.86 s
Temperature coefficient is only required for temperatures > 25C.
TACQ =
2002 Microchip Technology Inc.
DS39564B-page 185
PIC18FXX2
17.2 Selecting the A/D Conversion Clock 17.3 Configuring Analog Port Pins
The A/D conversion time per bit is defined as TAD. The A/D conversion requires 12 TAD per 10-bit conversion. The source of the A/D conversion clock is software selectable. The seven possible options for TAD are: * * * * * * * 2 TOSC 4 TOSC 8 TOSC 16 TOSC 32 TOSC 64 TOSC Internal A/D module RC oscillator (2-6 s) The ADCON1, TRISA and TRISE registers control the operation of the A/D port pins. The port pins that are desired as analog inputs, must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS2:CHS0 bits and the TRIS bits. Note 1: When reading the port register, all pins configured as analog input channels will read as cleared (a low level). Pins configured as digital inputs will convert an analog input. Analog levels on a digitally configured input will not affect the conversion accuracy. 2: Analog levels on any pin that is defined as a digital input (including the AN4:AN0 pins) may cause the input buffer to consume current that is out of the device's specification.
For correct A/D conversions, the A/D conversion clock (TAD) must be selected to ensure a minimum TAD time of 1.6 s. Table 17-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected.
TABLE 17-1:
TAD vs. DEVICE OPERATING FREQUENCIES
AD Clock Source (TAD) Maximum Device Frequency PIC18FXX2 1.25 MHz 2.50 MHz 5.00 MHz 10.00 MHz 20.00 MHz 40.00 MHz -- PIC18LFXX2 666 kHz 1.33 MHz 2.67 MHz 5.33 MHz 10.67 MHz 21.33 MHz --
Operation 2 TOSC 4 TOSC 8 TOSC 16 TOSC 32 TOSC 64 TOSC RC
ADCS2:ADCS0 000 100 001 101 010 110 011
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PIC18FXX2
17.4 A/D Conversions
Figure 17-3 shows the operation of the A/D converter after the GO bit has been set. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D result register pair will NOT be updated with the partially completed A/D conversion sample. That is, the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is aborted, a 2 TAD wait is required before the next acquisition is started. After this 2 TAD wait, acquisition on the selected channel is automatically started. The GO/DONE bit can then be set to start the conversion. Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D.
FIGURE 17-3:
A/D CONVERSION TAD CYCLES
b0
TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Conversion Starts Holding capacitor is disconnected from analog input (typically 100 ns) Set GO bit Next Q4: ADRESH/ADRESL is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is connected to analog input.
17.4.1
A/D RESULT REGISTERS
The ADRESH:ADRESL register pair is the location where the 10-bit A/D result is loaded at the completion of the A/D conversion. This register pair is 16-bits wide. The A/D module gives the flexibility to left or right justify the 10-bit result in the 16-bit result register. The A/D
Format Select bit (ADFM) controls this justification. Figure 17-4 shows the operation of the A/D result justification. The extra bits are loaded with '0's. When an A/D result will not overwrite these locations (A/D disable), these registers may be used as two general purpose 8-bit registers.
FIGURE 17-4:
A/D RESULT JUSTIFICATION
10-bit Result ADFM = 1 ADFM = 0
7 0000 00
2107
0
7
0765 0000 00
0
ADRESH
ADRESL
ADRESH
ADRESL
10-bit Result Right Justified
10-bit Result Left Justified
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PIC18FXX2
17.5 Use of the CCP2 Trigger
An A/D conversion can be started by the "special event trigger" of the CCP2 module. This requires that the CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be programmed as 1011 and that the A/D module is enabled (ADON bit is set). When the trigger occurs, the GO/ DONE bit will be set, starting the A/D conversion, and the Timer1 (or Timer3) counter will be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal software overhead (moving ADRESH/ADRESL to the desired location). The appropriate analog input channel must be selected and the minimum acquisition done before the "special event trigger" sets the GO/DONE bit (starts a conversion). If the A/D module is not enabled (ADON is cleared), the "special event trigger" will be ignored by the A/D module, but will still reset the Timer1 (or Timer3) counter.
TABLE 17-2:
Name INTCON PIR1 PIE1 IPR1 PIR2 PIE2 IPR2 ADRESH ADRESL ADCON0 ADCON1 PORTA TRISA PORTE LATE TRISE Bit 7 GIE/ GIEH
SUMMARY OF A/D REGISTERS
Bit 6 PEIE/ GIEL ADIF ADIE ADIP -- -- -- Bit 5 TMR0IE RCIF RCIE RCIP -- -- -- Bit 4 INT0IE TXIF TXIE TXIP EEIF EEIE EEIP Bit 3 RBIE SSPIF SSPIE SSPIP BCLIF BCLIE BCLIP Bit 2 TMR0IF CCP1IF CCP1IE CCP1IP LVDIF LVDIE LVDIP Bit 1 INT0IF TMR2IF TMR2IE TMR2IP TMR3IF TMR3IE TMR3IP Bit 0 RBIF TMR1IF TMR1IE TMR1IP CCP2IF CCP2IE CCP2IP Value on POR, BOR Value on All Other RESETS
0000 000x 0000 000u 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 ---0 0000 ---0 0000 ---0 0000 ---0 0000 ---1 1111 ---1 0000 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
PSPIF(1) PSPIE(1) PSPIP(1) -- -- --
A/D Result Register A/D Result Register ADCS1 ADFM -- -- -- -- IBF ADCS0 ADCS2 RA6 -- -- OBF CHS2 -- RA5 -- -- IBOV CHS1 -- RA4 -- -- PSPMODE CHS0 PCFG3 RA3 -- -- -- GO/DONE PCFG2 RA2 RE2 LATE2 -- PCFG1 RA1 RE1 LATE1 ADON PCFG0 RA0 RE0 LATE0
0000 00-0 0000 00-0 ---- -000 ---- -000 --0x 0000 --0u 0000 --11 1111 --11 1111 ---- -000 ---- -000 ---- -xxx ---- -uuu 0000 -111 0000 -111
PORTA Data Direction Register
PORTE Data Direction bits
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for A/D conversion. Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
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PIC18FXX2
18.0 LOW VOLTAGE DETECT
In many applications, the ability to determine if the device voltage (VDD) is below a specified voltage level is a desirable feature. A window of operation for the application can be created, where the application software can do "housekeeping tasks" before the device voltage exits the valid operating range. This can be done using the Low Voltage Detect module. This module is a software programmable circuitry, where a device voltage trip point can be specified. When the voltage of the device becomes lower then the specified point, an interrupt flag is set. If the interrupt is enabled, the program execution will branch to the interrupt vector address and the software can then respond to that interrupt source. The Low Voltage Detect circuitry is completely under software control. This allows the circuitry to be "turned off" by the software, which minimizes the current consumption for the device. Figure 18-1 shows a possible application voltage curve (typically for batteries). Over time, the device voltage decreases. When the device voltage equals voltage VA, the LVD logic generates an interrupt. This occurs at time TA. The application software then has the time, until the device voltage is no longer in valid operating range, to shutdown the system. Voltage point VB is the minimum valid operating voltage specification. This occurs at time TB. The difference TB - TA is the total time for shutdown.
FIGURE 18-1:
TYPICAL LOW VOLTAGE DETECT APPLICATION
Voltage
VA VB
Legend: VA = LVD trip point VB = Minimum valid device operating voltage TB
Time
TA
The block diagram for the LVD module is shown in Figure 18-2. A comparator uses an internally generated reference voltage as the set point. When the selected tap output of the device voltage crosses the set point (is lower than), the LVDIF bit is set. Each node in the resistor divider represents a "trip point" voltage. The "trip point" voltage is the minimum supply voltage level at which the device can operate before the LVD module asserts an interrupt. When the
supply voltage is equal to the trip point, the voltage tapped off of the resistor array is equal to the 1.2V internal reference voltage generated by the voltage reference module. The comparator then generates an interrupt signal setting the LVDIF bit. This voltage is software programmable to any one of 16 values (see Figure 18-2). The trip point is selected by programming the LVDL3:LVDL0 bits (LVDCON<3:0>).
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PIC18FXX2
FIGURE 18-2: LOW VOLTAGE DETECT (LVD) BLOCK DIAGRAM
VDD LVDIN LVD Control Register
16 to 1 MUX
- +
LVDIF
LVDEN
Internally Generated Reference Voltage 1.2V Typical
The LVD module has an additional feature that allows the user to supply the trip voltage to the module from an external source. This mode is enabled when bits LVDL3:LVDL0 are set to 1111. In this state, the comparator input is multiplexed from the external input pin,
LVDIN (Figure 18-3). This gives users flexibility, because it allows them to configure the Low Voltage Detect interrupt to occur at any voltage in the valid operating range.
FIGURE 18-3:
LOW VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM
VDD VDD LVD Control Register LVDIN 16 to 1 MUX LVDEN
- +
Externally Generated Trip Point
LVD
VxEN BODEN
EN BGAP
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PIC18FXX2
18.1 Control Register
The Low Voltage Detect Control register controls the operation of the Low Voltage Detect circuitry.
REGISTER 18-1:
LVDCON REGISTER
U-0 -- bit 7 U-0 -- R-0 IRVST R/W-0 LVDEN R/W-0 LVDL3 R/W-1 LVDL2 R/W-0 LVDL1 R/W-1 LVDL0 bit 0
bit 7-6 bit 5
Unimplemented: Read as '0' IRVST: Internal Reference Voltage Stable Flag bit 1 = Indicates that the Low Voltage Detect logic will generate the interrupt flag at the specified voltage range 0 = Indicates that the Low Voltage Detect logic will not generate the interrupt flag at the specified voltage range and the LVD interrupt should not be enabled LVDEN: Low Voltage Detect Power Enable bit 1 = Enables LVD, powers up LVD circuit 0 = Disables LVD, powers down LVD circuit LVDL3:LVDL0: Low Voltage Detection Limit bits 1111 = External analog input is used (input comes from the LVDIN pin) 1110 = 4.5V - 4.77V 1101 = 4.2V - 4.45V 1100 = 4.0V - 4.24V 1011 = 3.8V - 4.03V 1010 = 3.6V - 3.82V 1001 = 3.5V - 3.71V 1000 = 3.3V - 3.50V 0111 = 3.0V - 3.18V 0110 = 2.8V - 2.97V 0101 = 2.7V - 2.86V 0100 = 2.5V - 2.65V 0011 = 2.4V - 2.54V 0010 = 2.2V - 2.33V 0001 = 2.0V - 2.12V 0000 = Reserved Note: LVDL3:LVDL0 modes which result in a trip point below the valid operating voltage of the device are not tested.
bit 4
bit 3-0
Legend: R = Readable bit - n = Value at POR W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
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18.2 Operation
Depending on the power source for the device voltage, the voltage normally decreases relatively slowly. This means that the LVD module does not need to be constantly operating. To decrease the current requirements, the LVD circuitry only needs to be enabled for short periods, where the voltage is checked. After doing the check, the LVD module may be disabled. Each time that the LVD module is enabled, the circuitry requires some time to stabilize. After the circuitry has stabilized, all status flags may be cleared. The module will then indicate the proper state of the system. The following steps are needed to set up the LVD module: 1. Write the value to the LVDL3:LVDL0 bits (LVDCON register), which selects the desired LVD Trip Point. Ensure that LVD interrupts are disabled (the LVDIE bit is cleared or the GIE bit is cleared). Enable the LVD module (set the LVDEN bit in the LVDCON register). Wait for the LVD module to stabilize (the IRVST bit to become set). Clear the LVD interrupt flag, which may have falsely become set until the LVD module has stabilized (clear the LVDIF bit). Enable the LVD interrupt (set the LVDIE and the GIE bits).
2. 3. 4. 5.
6.
Figure 18-4 shows typical waveforms that the LVD module may be used to detect.
FIGURE 18-4:
CASE 1:
LOW VOLTAGE DETECT WAVEFORMS
LVDIF may not be set
VDD VLVD LVDIF Enable LVD Internally Generated Reference Stable TIVRST LVDIF cleared in software
CASE 2: VDD VLVD LVDIF Enable LVD Internally Generated Reference Stable TIVRST
LVDIF cleared in software LVDIF cleared in software, LVDIF remains set since LVD condition still exists
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PIC18FXX2
18.2.1 REFERENCE VOLTAGE SET POINT
18.3
Operation During SLEEP
The Internal Reference Voltage of the LVD module may be used by other internal circuitry (the Programmable Brown-out Reset). If these circuits are disabled (lower current consumption), the reference voltage circuit requires a time to become stable before a low voltage condition can be reliably detected. This time is invariant of system clock speed. This start-up time is specified in electrical specification parameter 36. The low voltage interrupt flag will not be enabled until a stable reference voltage is reached. Refer to the waveform in Figure 18-4.
When enabled, the LVD circuitry continues to operate during SLEEP. If the device voltage crosses the trip point, the LVDIF bit will be set and the device will wakeup from SLEEP. Device execution will continue from the interrupt vector address if interrupts have been globally enabled.
18.4
Effects of a RESET
A device RESET forces all registers to their RESET state. This forces the LVD module to be turned off.
18.2.2
CURRENT CONSUMPTION
When the module is enabled, the LVD comparator and voltage divider are enabled and will consume static current. The voltage divider can be tapped from multiple places in the resistor array. Total current consumption, when enabled, is specified in electrical specification parameter #D022B.
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NOTES:
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PIC18FXX2
19.0 SPECIAL FEATURES OF THE CPU
19.1 Configuration Bits
The configuration bits can be programmed (read as '0'), or left unprogrammed (read as '1'), to select various device configurations. These bits are mapped starting at program memory location 300000h. The user will note that address 300000h is beyond the user program memory space. In fact, it belongs to the configuration memory space (300000h - 3FFFFFh), which can only be accessed using Table Reads and Table Writes. Programming the configuration registers is done in a manner similar to programming the FLASH memory (see Section 5.5.1). The only difference is the configuration registers are written a byte at a time. The sequence of events for programming configuration registers is: Load table pointer with address of configuration register being written. 2. Write a single byte using the TBLWT instruction. 3. Set EEPGD to point to program memory, set the CFGS bit to access configuration registers, and set WREN to enable byte writes. 4. Disable interrupts. 5. Write 55h to EECON2. 6. Write AAh to EECON2. 7. Set the WR bit. This will begin the write cycle. 8. CPU will stall for duration of write (approximately 2 ms using internal timer). 9. Execute a NOP. 10. Re-enable interrupts. 1.
There are several features intended to maximize system reliability, minimize cost through elimination of external components, provide power saving Operating modes and offer code protection. These are: * OSC Selection * RESET - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) * Interrupts * Watchdog Timer (WDT) * SLEEP * Code Protection * ID Locations * In-Circuit Serial Programming All PIC18FXX2 devices have a Watchdog Timer, which is permanently enabled via the configuration bits or software controlled. It runs off its own RC oscillator for added reliability. There are two timers that offer necessary delays on power-up. One is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable. The other is the Powerup Timer (PWRT), which provides a fixed delay on power-up only, designed to keep the part in RESET while the power supply stabilizes. With these two timers on-chip, most applications need no external RESET circuitry. SLEEP mode is designed to offer a very low current Power-down mode. The user can wake-up from SLEEP through external RESET, Watchdog Timer Wake-up or through an interrupt. Several oscillator options are also made available to allow the part to fit the application. The RC oscillator option saves system cost, while the LP crystal option saves power. A set of configuration bits are used to select various options.
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TABLE 19-1:
File Name
CONFIGURATION BITS AND DEVICE IDS
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Default/ Unprogrammed Value
300001h 300002h 300003h 300005h 300006h 300008h 300009h 30000Ah 30000Bh 30000Ch 30000Dh 3FFFFEh 3FFFFFh
CONFIG1H CONFIG2L CONFIG2H CONFIG3H CONFIG4L CONFIG5L CONFIG5H CONFIG6L CONFIG6H CONFIG7L CONFIG7H DEVID1 DEVID2
-- -- -- -- DEBUG -- CPD -- WRTD -- -- DEV2 DEV10
-- -- -- -- -- -- CPB -- WRTB -- EBTRB DEV1 DEV9
OSCSEN -- -- -- -- -- -- -- WRTC -- -- DEV0 DEV8
-- -- -- -- -- -- -- -- -- -- -- REV4 DEV7
-- BORV1 WDTPS2 -- -- CP3 -- WRT3 -- EBTR3 -- REV3 DEV6
FOSC2 BORV0 WDTPS1 -- LVP CP2 -- WRT2 -- EBTR2 -- REV2 DEV5
FOSC1 BOREN WDTPS0 -- -- CP1 -- WRT1 -- EBTR1 -- REV1 DEV4
FOSC0 PWRTEN WDTEN CCP2MX STVREN CP0 -- WRT0 -- EBTR0 -- REV0 DEV3
--1- -111 ---- 1111 ---- 1111 ---- ---1 1--- -1-1 ---- 1111 11-- ------- 1111 111- ------- 1111 -1-- ---(1)
0000 0100
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. Shaded cells are unimplemented, read as `0'. Note 1: See Register 19-12 for DEVID1 values.
REGISTER 19-1:
CONFIGURATION REGISTER 1 HIGH (CONFIG1H: BYTE ADDRESS 300001h)
U-0 -- bit 7 U-0 -- R/P-1 OSCSEN U-0 -- U-0 -- R/P-1 FOSC2 R/P-1 FOSC1 R/P-1 FOSC0 bit 0
bit 7-6 bit 5
Unimplemented: Read as `0' OSCSEN: Oscillator System Clock Switch Enable bit 1 = Oscillator system clock switch option is disabled (main oscillator is source) 0 = Oscillator system clock switch option is enabled (oscillator switching is enabled) Unimplemented: Read as `0' FOSC2:FOSC0: Oscillator Selection bits 111 = RC oscillator w/ OSC2 configured as RA6 110 = HS oscillator with PLL enabled/Clock frequency = (4 x FOSC) 101 = EC oscillator w/ OSC2 configured as RA6 100 = EC oscillator w/ OSC2 configured as divide-by-4 clock output 011 = RC oscillator 010 = HS oscillator 001 = XT oscillator 000 = LP oscillator Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed
bit 4-3 bit 2-0
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PIC18FXX2
REGISTER 19-2: CONFIGURATION REGISTER 2 LOW (CONFIG2L: BYTE ADDRESS 300002h)
U-0 -- bit 7 bit 7-4 bit 3-2 Unimplemented: Read as `0' BORV1:BORV0: Brown-out Reset Voltage bits 11 = VBOR set to 2.5V 10 = VBOR set to 2.7V 01 = VBOR set to 4.2V 00 = VBOR set to 4.5V BOREN: Brown-out Reset Enable bit 1 = Brown-out Reset enabled 0 = Brown-out Reset disabled PWRTEN: Power-up Timer Enable bit 1 = PWRT disabled 0 = PWRT enabled Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed U-0 -- U-0 -- U-0 -- R/P-1 BORV1 R/P-1 BORV0 R/P-1 BOREN R/P-1 PWRTEN bit 0
bit 1
bit 0
REGISTER 19-3:
CONFIGURATION REGISTER 2 HIGH (CONFIG2H: BYTE ADDRESS 300003h)
U-0 -- bit 7 U-0 -- U-0 -- U-0 -- R/P-1 WDTPS2 R/P-1 WDTPS1 R/P-1 WDTPS0 R/P-1 WDTEN bit 0
bit 7-4 bit 3-1
Unimplemented: Read as `0' WDTPS2:WDTPS0: Watchdog Timer Postscale Select bits 111 = 1:128 110 = 1:64 101 = 1:32 100 = 1:16 011 = 1:8 010 = 1:4 001 = 1:2 000 = 1:1 WDTEN: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled (control is placed on the SWDTEN bit) Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed
bit 0
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REGISTER 19-4: CONFIGURATION REGISTER 3 HIGH (CONFIG3H: BYTE ADDRESS 300005h)
U-0 -- bit 7 bit 7-1 bit 0 Unimplemented: Read as `0' CCP2MX: CCP2 Mux bit 1 = CCP2 input/output is multiplexed with RC1 0 = CCP2 input/output is multiplexed with RB3 Legend: R = Readable bit P = Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- R/P-1 CCP2MX bit 0
REGISTER 19-5:
CONFIGURATION REGISTER 4 LOW (CONFIG4L: BYTE ADDRESS 300006h)
R/P-1 BKBUG bit 7 U-0 -- U-0 -- U-0 -- U-0 -- R/P-1 LVP U-0 -- R/P-1 STVREN bit 0
bit 7
DEBUG: Background Debugger Enable bit 1 = Background Debugger disabled. RB6 and RB7 configured as general purpose I/O pins. 0 = Background Debugger enabled. RB6 and RB7 are dedicated to In-Circuit Debug. Unimplemented: Read as `0' LVP: Low Voltage ICSP Enable bit 1 = Low Voltage ICSP enabled 0 = Low Voltage ICSP disabled Unimplemented: Read as `0' STVREN: Stack Full/Underflow Reset Enable bit 1 = Stack Full/Underflow will cause RESET 0 = Stack Full/Underflow will not cause RESET Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed
bit 6-3 bit 2
bit 1 bit 0
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PIC18FXX2
REGISTER 19-6: CONFIGURATION REGISTER 5 LOW (CONFIG5L: BYTE ADDRESS 300008h)
U-0 -- bit 7 bit 7-4 bit 3 Unimplemented: Read as `0' CP3: Code Protection bit(1) 1 = Block 3 (006000-007FFFh) not code protected 0 = Block 3 (006000-007FFFh) code protected CP2: Code Protection bit(1) 1 = Block 2 (004000-005FFFh) not code protected 0 = Block 2 (004000-005FFFh) code protected CP1: Code Protection bit 1 = Block 1 (002000-003FFFh) not code protected 0 = Block 1 (002000-003FFFh) code protected CP0: Code Protection bit 1 = Block 0 (000200-001FFFh) not code protected 0 = Block 0 (000200-001FFFh) code protected Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set. Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed U-0 -- U-0 -- U-0 -- R/C-1 CP3
(1)
R/C-1 CP2
(1)
R/C-1 CP1
R/C-1 CP0 bit 0
bit 2
bit 1
bit 0
REGISTER 19-7:
CONFIGURATION REGISTER 5 HIGH (CONFIG5H: BYTE ADDRESS 300009h)
R/C-1 CPD bit 7 R/C-1 CPB U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- bit 0
bit 7
CPD: Data EEPROM Code Protection bit 1 = Data EEPROM not code protected 0 = Data EEPROM code protected CPB: Boot Block Code Protection bit 1 = Boot Block (000000-0001FFh) not code protected 0 = Boot Block (000000-0001FFh) code protected Unimplemented: Read as `0' Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed
bit 6
bit 5-0
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PIC18FXX2
REGISTER 19-8: CONFIGURATION REGISTER 6 LOW (CONFIG6L: BYTE ADDRESS 30000Ah)
U-0 -- bit 7 bit 7-4 bit 3 Unimplemented: Read as `0' WRT3: Write Protection bit(1) 1 = Block 3 (006000-007FFFh) not write protected 0 = Block 3 (006000-007FFFh) write protected WRT2: Write Protection bit(1) 1 = Block 2 (004000-005FFFh) not write protected 0 = Block 2 (004000-005FFFh) write protected WRT1: Write Protection bit 1 = Block 1 (002000-003FFFh) not write protected 0 = Block 1 (002000-003FFFh) write protected WRT0: Write Protection bit 1 = Block 0 (000200h-001FFFh) not write protected 0 = Block 0 (000200h-001FFFh) write protected Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set. Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed U-0 -- U-0 -- U-0 -- R/C-1 WRT3
(1)
R/C-1 WRT2
(1)
R/C-1 WRT1
R/C-1 WRT0 bit 0
bit 2
bit 1
bit 0
REGISTER 19-9:
CONFIGURATION REGISTER 6 HIGH (CONFIG6H: BYTE ADDRESS 30000Bh)
R/C-1 WRTD bit 7 R/C-1 WRTB C-1 WRTC U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- bit 0
bit 7
WRTD: Data EEPROM Write Protection bit 1 = Data EEPROM not write protected 0 = Data EEPROM write protected WRTB: Boot Block Write Protection bit 1 = Boot Block (000000-0001FFh) not write protected 0 = Boot Block (000000-0001FFh) write protected WRTC: Configuration Register Write Protection bit 1 = Configuration registers (300000-3000FFh) not write protected 0 = Configuration registers (300000-3000FFh) write protected Note: This bit is read only, and cannot be changed in User mode. Unimplemented: Read as `0' Legend: R = Readable bit C =Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed
bit 6
bit 5
bit 4-0
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PIC18FXX2
REGISTER 19-10: CONFIGURATION REGISTER 7 LOW (CONFIG7L: BYTE ADDRESS 30000Ch)
U-0 -- bit 7 bit 7-4 bit 3 Unimplemented: Read as `0' EBTR3: Table Read Protection bit(1) 1 = Block 3 (006000-007FFFh) not protected from Table Reads executed in other blocks 0 = Block 3 (006000-007FFFh) protected from Table Reads executed in other blocks EBTR2: Table Read Protection bit(1) 1 = Block 2 (004000-005FFFh) not protected from Table Reads executed in other blocks 0 = Block 2 (004000-005FFFh) protected from Table Reads executed in other blocks EBTR1: Table Read Protection bit 1 = Block 1 (002000-003FFFh) not protected from Table Reads executed in other blocks 0 = Block 1 (002000-003FFFh) protected from Table Reads executed in other blocks EBTR0: Table Read Protection bit 1 = Block 0 (000200h-001FFFh) not protected from Table Reads executed in other blocks 0 = Block 0 (000200h-001FFFh) protected from Table Reads executed in other blocks Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set. Legend: R = Readable bit C = Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed U-0 -- U-0 -- U-0 -- R/C-1 EBTR3(1) R/C-1 EBTR2(1) R/C-1 EBTR1 R/C-1 EBTR0 bit 0
bit 2
bit 1
bit 0
REGISTER 19-11: CONFIGURATION REGISTER 7 HIGH (CONFIG7H: BYTE ADDRESS 30000Dh)
U-0 -- bit 7 bit 7 bit 6 Unimplemented: Read as `0' EBTRB: Boot Block Table Read Protection bit 1 = Boot Block (000000-0001FFh) not protected from Table Reads executed in other blocks 0 = Boot Block (000000-0001FFh) protected from Table Reads executed in other blocks Unimplemented: Read as `0' Legend: R = Readable bit C =Clearable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed R/C-1 EBTRB U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- bit 0
bit 5-0
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PIC18FXX2
REGISTER 19-12: DEVICE ID REGISTER 1 FOR PIC18FXX2 (DEVID1: BYTE ADDRESS 3FFFFEh)
R DEV2 bit 7 bit 7-5 DEV2:DEV0: Device ID bits 000 = PIC18F252 001 = PIC18F452 100 = PIC18F242 101 = PIC18F442 REV4:REV0: Revision ID bits These bits are used to indicate the device revision. Legend: R = Readable bit P =Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed R DEV1 R DEV0 R REV4 R REV3 R REV2 R REV1 R REV0 bit 0
bit 4-0
REGISTER 19-13: DEVICE ID REGISTER 2 FOR PIC18FXX2 (DEVID2: BYTE ADDRESS 3FFFFFh)
R DEV10 bit 7 bit 7-0 DEV10:DEV3: Device ID bits These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the part number. Legend: R = Readable bit P =Programmable bit U = Unimplemented bit, read as `0' u = Unchanged from programmed state - n = Value when device is unprogrammed R DEV9 R DEV8 R DEV7 R DEV6 R DEV5 R DEV4 R DEV3 bit 0
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PIC18FXX2
19.2 Watchdog Timer (WDT)
The Watchdog Timer is a free running on-chip RC oscillator, which does not require any external components. This RC oscillator is separate from the RC oscillator of the OSC1/CLKI pin. That means that the WDT will run, even if the clock on the OSC1/CLKI and OSC2/CLKO/ RA6 pins of the device has been stopped, for example, by execution of a SLEEP instruction. During normal operation, a WDT time-out generates a device RESET (Watchdog Timer Reset). If the device is in SLEEP mode, a WDT time-out causes the device to wake-up and continue with normal operation (Watchdog Timer Wake-up). The TO bit in the RCON register will be cleared upon a WDT time-out. The Watchdog Timer is enabled/disabled by a device configuration bit. If the WDT is enabled, software execution may not disable this function. When the WDTEN configuration bit is cleared, the SWDTEN bit enables/ disables the operation of the WDT. The WDT time-out period values may be found in the Electrical Specifications (Section 22.0) under parameter D031. Values for the WDT postscaler may be assigned using the configuration bits. Note: The CLRWDT and SLEEP instructions clear the WDT and the postscaler, if assigned to the WDT and prevent it from timing out and generating a device RESET condition.
Note:
When a CLRWDT instruction is executed and the postscaler is assigned to the WDT, the postscaler count will be cleared, but the postscaler assignment is not changed.
19.2.1
CONTROL REGISTER
Register 19-14 shows the WDTCON register. This is a readable and writable register, which contains a control bit that allows software to override the WDT enable configuration bit, only when the configuration bit has disabled the WDT.
REGISTER 19-14: WDTCON REGISTER
U-0 -- bit 7 bit 7-1 bit 0 Unimplemented: Read as '0' SWDTEN: Software Controlled Watchdog Timer Enable bit 1 = Watchdog Timer is on 0 = Watchdog Timer is turned off if the WDTEN configuration bit in the configuration register = `0' Legend: R = Readable bit U = Unimplemented bit, read as `0' W = Writable bit - n = Value at POR U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- U-0 -- R/W-0 SWDTEN bit 0
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19.2.2 WDT POSTSCALER
The WDT has a postscaler that can extend the WDT Reset period. The postscaler is selected at the time of the device programming, by the value written to the CONFIG2H configuration register.
FIGURE 19-1:
WATCHDOG TIMER BLOCK DIAGRAM
WDT Timer
Postscaler 8 8 - to - 1 MUX WDTPS2:WDTPS0
WDTEN Configuration bit
SWDTEN bit
WDT Time-out Note: WDPS2:WDPS0 are bits in register CONFIG2H.
TABLE 19-2:
Name CONFIG2H RCON WDTCON
SUMMARY OF WATCHDOG TIMER REGISTERS
Bit 7 -- IPEN -- Bit 6 -- -- -- Bit 5 -- -- -- Bit 4 -- RI -- Bit 3 WDTPS2 TO -- Bit 2 WDTPS2 PD -- Bit 1 WDTPS0 POR -- Bit 0 WDTEN BOR SWDTEN
Legend: Shaded cells are not used by the Watchdog Timer.
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PIC18FXX2
19.3 Power-down Mode (SLEEP)
Power-down mode is entered by executing a SLEEP instruction. If enabled, the Watchdog Timer will be cleared, but keeps running, the PD bit (RCON<3>) is cleared, the TO (RCON<4>) bit is set, and the oscillator driver is turned off. The I/O ports maintain the status they had before the SLEEP instruction was executed (driving high, low or hi-impedance). For lowest current consumption in this mode, place all I/O pins at either VDD or VSS, ensure no external circuitry is drawing current from the I/O pin, power-down the A/D and disable external clocks. Pull all I/O pins that are hi-impedance inputs, high or low externally, to avoid switching currents caused by floating inputs. The T0CKI input should also be at VDD or VSS for lowest current consumption. The contribution from on-chip pull-ups on PORTB should be considered. The MCLR pin must be at a logic high level (VIHMC). External MCLR Reset will cause a device RESET. All other events are considered a continuation of program execution and will cause a "wake-up". The TO and PD bits in the RCON register can be used to determine the cause of the device RESET. The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The TO bit is cleared, if a WDT time-out occurred (and caused wake-up). When the SLEEP instruction is being executed, the next instruction (PC + 2) is pre-fetched. For the device to wake-up through an interrupt event, the corresponding interrupt enable bit must be set (enabled). Wake-up is regardless of the state of the GIE bit. If the GIE bit is clear (disabled), the device continues execution at the instruction after the SLEEP instruction. If the GIE bit is set (enabled), the device executes the instruction after the SLEEP instruction and then branches to the interrupt address. In cases where the execution of the instruction following SLEEP is not desirable, the user should have a NOP after the SLEEP instruction.
19.3.1
WAKE-UP FROM SLEEP
19.3.2
WAKE-UP USING INTERRUPTS
The device can wake-up from SLEEP through one of the following events: 1. 2. 3. External RESET input on MCLR pin. Watchdog Timer Wake-up (if WDT was enabled). Interrupt from INT pin, RB port change or a Peripheral Interrupt.
When global interrupts are disabled (GIE cleared) and any interrupt source has both its interrupt enable bit and interrupt flag bit set, one of the following will occur: * If an interrupt condition (interrupt flag bit and interrupt enable bits are set) occurs before the execution of a SLEEP instruction, the SLEEP instruction will complete as a NOP. Therefore, the WDT and WDT postscaler will not be cleared, the TO bit will not be set and PD bits will not be cleared. * If the interrupt condition occurs during or after the execution of a SLEEP instruction, the device will immediately wake-up from SLEEP. The SLEEP instruction will be completely executed before the wake-up. Therefore, the WDT and WDT postscaler will be cleared, the TO bit will be set and the PD bit will be cleared. Even if the flag bits were checked before executing a SLEEP instruction, it may be possible for flag bits to become set before the SLEEP instruction completes. To determine whether a SLEEP instruction executed, test the PD bit. If the PD bit is set, the SLEEP instruction was executed as a NOP. To ensure that the WDT is cleared, a CLRWDT instruction should be executed before a SLEEP instruction.
The following peripheral interrupts can wake the device from SLEEP: PSP read or write. TMR1 interrupt. Timer1 must be operating as an asynchronous counter. 3. TMR3 interrupt. Timer3 must be operating as an asynchronous counter. 4. CCP Capture mode interrupt. 5. Special event trigger (Timer1 in Asynchronous mode using an external clock). 6. MSSP (START/STOP) bit detect interrupt. 7. MSSP transmit or receive in Slave mode (SPI/I2C). 8. USART RX or TX (Synchronous Slave mode). 9. A/D conversion (when A/D clock source is RC). 10. EEPROM write operation complete. 11. LVD interrupt. Other peripherals cannot generate interrupts, since during SLEEP, no on-chip clocks are present. 1. 2.
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PIC18FXX2
FIGURE 19-2:
OSC1 CLKO(4) INT pin INTF flag (INTCON<1>) GIEH bit (INTCON<7>) INSTRUCTION FLOW PC Instruction Fetched Instruction Executed PC Inst(PC) = SLEEP Inst(PC - 1) PC+2 Inst(PC + 2) SLEEP PC+4 PC+4 Inst(PC + 4) Inst(PC + 2) Dummy Cycle PC + 4 0008h Inst(0008h) Dummy Cycle 000Ah Inst(000Ah) Inst(0008h) Processor in SLEEP Interrupt Latency(3) TOST(2)
WAKE-UP FROM SLEEP THROUGH INTERRUPT(1,2)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1
Note
1: 2: 3: 4:
XT, HS or LP Oscillator mode assumed. GIE = '1' assumed. In this case, after wake-up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line. TOST = 1024 TOSC (drawing not to scale). This delay will not occur for RC and EC Osc modes. CLKO is not available in these Osc modes, but shown here for timing reference.
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PIC18FXX2
19.4 Program Verification and Code Protection
Each of the five blocks has three code protection bits associated with them. They are: * Code Protect bit (CPn) * Write Protect bit (WRTn) * External Block Table Read bit (EBTRn) Figure 19-3 shows the program memory organization for 16- and 32-Kbyte devices, and the specific code protection bit associated with each block. The actual locations of the bits are summarized in Table 19-3.
The overall structure of the code protection on the PIC18 FLASH devices differs significantly from other PICmicro devices. The user program memory is divided into five blocks. One of these is a boot block of 512 bytes. The remainder of the memory is divided into four blocks on binary boundaries.
FIGURE 19-3:
CODE PROTECTED PROGRAM MEMORY FOR PIC18F2XX/4XX
MEMORY SIZE/DEVICE Block Code Protection Controlled By:
16 Kbytes (PIC18FX42) Boot Block
32 Kbytes (PIC18FX52) Boot Block
Address Range 000000h 0001FFh 000200h
CPB, WRTB, EBTRB
Block 0
Block 0 001FFFh 002000h
CP0, WRT0, EBTR0
Block 1
Block 1 003FFFh 004000h Block 2 005FFFh 006000h Block 3 007FFFh 008000h
CP1, WRT1, EBTR1
Unimplemented Read 0's Unimplemented Read 0's
CP2, WRT2, EBTR2
CP3, WRT3, EBTR3
Unimplemented Read 0's
Unimplemented Read 0's
(Unimplemented Memory Space)
1FFFFFh
TABLE 19-3:
SUMMARY OF CODE PROTECTION REGISTERS
Bit 7 -- CPD -- WRTD -- -- Bit 6 -- CPB -- WRTB -- EBTRB Bit 5 -- -- -- WRTC -- -- Bit 4 -- -- -- -- -- -- Bit 3 CP3 -- WRT3 -- EBTR3 -- Bit 2 CP2 -- WRT2 -- EBTR2 -- Bit 1 CP1 -- WRT1 -- EBTR1 -- Bit 0 CP0 -- WRT0 -- EBTR0 --
File Name 300008h 300009h 30000Ah 30000Bh 30000Ch 30000Dh CONFIG5L CONFIG5H CONFIG6L CONFIG6H CONFIG7L CONFIG7H
Legend: Shaded cells are unimplemented.
2002 Microchip Technology Inc.
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PIC18FXX2
19.4.1 PROGRAM MEMORY CODE PROTECTION
outside of that block is not allowed to read, and will result in reading `0's. Figures 19-4 through 19-6 illustrate Table Write and Table Read protection.
The user memory may be read to or written from any location using the Table Read and Table Write instructions. The device ID may be read with Table Reads. The configuration registers may be read and written with the Table Read and Table Write instructions. In User mode, the CPn bits have no direct effect. CPn bits inhibit external reads and writes. A block of user memory may be protected from Table Writes if the WRTn configuration bit is `0'. The EBTRn bits control Table Reads. For a block of user memory with the EBTRn bit set to `0', a Table Read instruction that executes from within that block is allowed to read. A Table Read instruction that executes from a location
Note:
Code protection bits may only be written to a `0' from a `1' state. It is not possible to write a `1' to a bit in the `0' state. Code protection bits are only set to `1' by a full chip erase or block erase function. The full chip erase and block erase functions can only be initiated via ICSP or an external programmer.
FIGURE 19-4:
TABLE WRITE (WRTn) DISALLOWED
Program Memory 000000h 0001FFh 000200h WRTB,EBTRB = 11 Configuration Bit Settings
Register Values
TBLPTR = 000FFF WRT0,EBTR0 = 01 PC = 001FFE TBLWT * 001FFFh 002000h WRT1,EBTR1 = 11 003FFFh 004000h PC = 004FFE TBLWT * 005FFFh 006000h WRT3,EBTR3 = 11 007FFFh Results: All Table Writes disabled to Blockn whenever WRTn = `0'. WRT2,EBTR2 = 11
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PIC18FXX2
FIGURE 19-5: EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Program Memory 000000h WRTB,EBTRB = 11 0001FFh 000200h TBLPTR = 000FFF WRT0,EBTR0 = 10 001FFFh 002000h PC = 002FFE TBLRD * 003FFFh 004000h WRT2,EBTR2 = 11 005FFFh 006000h WRT3,EBTR3 = 11 007FFFh Results: All Table Reads from external blocks to Blockn are disabled whenever EBTRn = `0'. TABLAT register returns a value of "0". WRT1,EBTR1 = 11 Configuration Bit Settings Register Values
FIGURE 19-6:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Program Memory 000000h WRTB,EBTRB = 11 0001FFh 000200h Configuration Bit Settings
Register Values
TBLPTR = 000FFF PC = 001FFE TBLRD * 001FFFh 002000h
WRT0,EBTR0 = 10
WRT1,EBTR1 = 11 003FFFh 004000h WRT2,EBTR2 = 11 005FFFh 006000h WRT3,EBTR3 = 11 007FFFh Results: Table Reads permitted within Blockn, even when EBTRBn = `0'. TABLAT register returns the value of the data at the location TBLPTR.
2002 Microchip Technology Inc.
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PIC18FXX2
19.4.2 DATA EEPROM CODE PROTECTION
To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to MCLR/VPP, VDD, GND, RB7 and RB6. This will interface to the In-Circuit Debugger module available from Microchip or one of the third party development tool companies.
The entire Data EEPROM is protected from external reads and writes by two bits: CPD and WRTD. CPD inhibits external reads and writes of Data EEPROM. WRTD inhibits external writes to Data EEPROM. The CPU can continue to read and write Data EEPROM regardless of the protection bit settings.
19.8
Low Voltage ICSP Programming
19.4.3
CONFIGURATION REGISTER PROTECTION
The configuration registers can be write protected. The WRTC bit controls protection of the configuration registers. In User mode, the WRTC bit is readable only. WRTC can only be written via ICSP or an external programmer.
19.5
ID Locations
Eight memory locations (200000h - 200007h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are accessible during normal execution through the TBLRD and TBLWT instructions, or during program/verify. The ID locations can be read when the device is code protected. The sequence for programming the ID locations is similar to programming the FLASH memory (see Section 5.5.1).
The LVP bit configuration register CONFIG4L enables low voltage ICSP programming. This mode allows the microcontroller to be programmed via ICSP using a VDD source in the operating voltage range. This only means that VPP does not have to be brought to VIHH, but can instead be left at the normal operating voltage. In this mode, the RB5/PGM pin is dedicated to the programming function and ceases to be a general purpose I/O pin. During programming, VDD is applied to the MCLR/VPP pin. To enter Programming mode, VDD must be applied to the RB5/PGM, provided the LVP bit is set. The LVP bit defaults to a (`1') from the factory. Note 1: The High Voltage Programming mode is always available, regardless of the state of the LVP bit, by applying VIHH to the MCLR pin. 2: While in low voltage ICSP mode, the RB5 pin can no longer be used as a general purpose I/O pin, and should be held low during normal operation to protect against inadvertent ICSP mode entry. 3: When using low voltage ICSP programming (LVP), the pull-up on RB5 becomes disabled. If TRISB bit 5 is cleared, thereby setting RB5 as an output, LATB bit 5 must also be cleared for proper operation. If Low Voltage Programming mode is not used, the LVP bit can be programmed to a '0' and RB5/PGM becomes a digital I/O pin. However, the LVP bit may only be programmed when programming is entered with VIHH on MCLR/VPP. It should be noted that once the LVP bit is programmed to 0, only the High Voltage Programming mode is available and only High Voltage Programming mode can be used to program the device. When using low voltage ICSP, the part must be supplied 4.5V to 5.5V, if a bulk erase will be executed. This includes reprogramming of the code protect bits from an on-state to off-state. For all other cases of low voltage ICSP, the part may be programmed at the normal operating voltage. This means unique user IDs, or user code can be reprogrammed or added.
19.6
In-Circuit Serial Programming
PIC18FXXX microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data, and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices, and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed.
19.7
In-Circuit Debugger
When the DEBUG bit in configuration register CONFIG4L is programmed to a '0', the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB(R) IDE. When the microcontroller has this feature enabled, some of the resources are not available for general use. Table 19-4 shows which features are consumed by the background debugger.
TABLE 19-4:
I/O pins Stack
DEBUGGER RESOURCES
RB6, RB7 2 levels 512 bytes 10 bytes
Program Memory Data Memory
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PIC18FXX2
20.0 INSTRUCTION SET SUMMARY
The literal instructions may use some of the following operands: * A literal value to be loaded into a file register (specified by `k') * The desired FSR register to load the literal value into (specified by `f') * No operand required (specified by `--') The control instructions may use some of the following operands: * A program memory address (specified by `n') * The mode of the Call or Return instructions (specified by `s') * The mode of the Table Read and Table Write instructions (specified by `m') * No operand required (specified by `--') All instructions are a single word, except for three double-word instructions. These three instructions were made double-word instructions so that all the required information is available in these 32 bits. In the second word, the 4-MSbs are 1's. If this second word is executed as an instruction (by itself), it will execute as a NOP. All single word instructions are executed in a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruction. In these cases, the execution takes two instruction cycles with the additional instruction cycle(s) executed as a NOP. The double-word instructions execute in two instruction cycles. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 s. If a conditional test is true or the program counter is changed as a result of an instruction, the instruction execution time is 2 s. Two-word branch instructions (if true) would take 3 s. Figure 20-1 shows the general formats that the instructions can have. All examples use the format `nnh' to represent a hexadecimal number, where `h' signifies a hexadecimal digit. The Instruction Set Summary, shown in Table 20-2, lists the instructions recognized by the Microchip Assembler (MPASMTM). Section 20.1 provides a description of each instruction. The PIC18FXXX instruction set adds many enhancements to the previous PICmicro instruction sets, while maintaining an easy migration from these PICmicro instruction sets. Most instructions are a single program memory word (16-bits), but there are three instructions that require two program memory locations. Each single word instruction is a 16-bit word divided into an OPCODE, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. The instruction set is highly orthogonal and is grouped into four basic categories: * * * * Byte-oriented operations Bit-oriented operations Literal operations Control operations
The PIC18FXXX instruction set summary in Table 20-2 lists byte-oriented, bit-oriented, literal and control operations. Table 20-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. 2. 3. The file register (specified by `f') The destination of the result (specified by `d') The accessed memory (specified by `a')
The file register designator 'f' specifies which file register is to be used by the instruction. The destination designator `d' specifies where the result of the operation is to be placed. If 'd' is zero, the result is placed in the WREG register. If 'd' is one, the result is placed in the file register specified in the instruction. All bit-oriented instructions have three operands: 1. 2. 3. The file register (specified by `f') The bit in the file register (specified by `b') The accessed memory (specified by `a')
The bit field designator 'b' selects the number of the bit affected by the operation, while the file register designator 'f' represents the number of the file in which the bit is located.
2002 Microchip Technology Inc.
DS39564B-page 211
PIC18FXX2
TABLE 20-1:
Field
a
OPCODE FIELD DESCRIPTIONS
Description RAM access bit a = 0: RAM location in Access RAM (BSR register is ignored) a = 1: RAM bank is specified by BSR register Bit address within an 8-bit file register (0 to 7) Bank Select Register. Used to select the current RAM bank. Destination select bit; d = 0: store result in WREG, d = 1: store result in file register f. Destination either the WREG register or the specified register file location 8-bit Register file address (0x00 to 0xFF) 12-bit Register file address (0x000 to 0xFFF). This is the source address. 12-bit Register file address (0x000 to 0xFFF). This is the destination address. Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value) Label name The mode of the TBLPTR register for the Table Read and Table Write instructions. Only used with Table Read and Table Write instructions: No Change to register (such as TBLPTR with Table reads and writes) Post-Increment register (such as TBLPTR with Table reads and writes) Post-Decrement register (such as TBLPTR with Table reads and writes) Pre-Increment register (such as TBLPTR with Table reads and writes) The relative address (2's complement number) for relative branch instructions, or the direct address for Call/Branch and Return instructions Product of Multiply high byte Product of Multiply low byte Fast Call/Return mode select bit. s = 0: do not update into/from shadow registers s = 1: certain registers loaded into/from shadow registers (Fast mode) Unused or Unchanged Working register (accumulator) Don't care (0 or 1) The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. 21-bit Table Pointer (points to a Program Memory location) 8-bit Table Latch Top-of-Stack Program Counter Program Counter Low Byte Program Counter High Byte Program Counter High Byte Latch Program Counter Upper Byte Latch Global Interrupt Enable bit Watchdog Timer Time-out bit Power-down bit
bbb BSR d
dest f fs fd k label mm * *+ *+* n PRODH PRODL s
u WREG x
TBLPTR TABLAT TOS PC PCL PCH PCLATH PCLATU GIE WDT TO PD [ ( <> italics ] )
C, DC, Z, OV, N ALU status bits Carry, Digit Carry, Zero, Overflow, Negative
Optional Contents Assigned to Register bit field In the set of User defined term (font is courier)
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PIC18FXX2
FIGURE 20-1: GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations 15 10 9 87 OPCODE d a 0 f (FILE #) ADDWF MYREG, W, B Example Instruction
d = 0 for result destination to be WREG register d = 1 for result destination to be file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Byte to Byte move operations (2-word) 15 12 11 OPCODE 15 12 11
1111
0 f (Source FILE #) 0 f (Destination FILE #) MOVFF MYREG1, MYREG2
f = 12-bit file register address Bit-oriented file register operations 15 12 11 98 7 f (FILE #) 0 BSF MYREG, bit, B
OPCODE b (BIT #) a
b = 3-bit position of bit in file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Literal operations 15 OPCODE k = 8-bit immediate value Control operations CALL, GOTO and Branch operations 15 OPCODE 15
1111
8
7 k (literal)
0 MOVLW 0x7F
87 n<7:0> (literal)
0 GOTO Label
12 11 n<19:8> (literal)
0
n = 20-bit immediate value 15 OPCODE 15 12 11 n<19:8> (literal) S = Fast bit 15 OPCODE 15 OPCODE 11 10 n<10:0> (literal) 87 n<7:0> (literal) 0 BC MYFUNC 0 BRA MYFUNC 87 S n<7:0> (literal) 0 0 CALL MYFUNC
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PIC18FXX2
TABLE 20-2:
Mnemonic, Operands
PIC18FXXX INSTRUCTION SET
16-Bit Instruction Word Description Cycles MSb LSb Status Affected Notes
BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB SUBWF SUBWFB SWAPF TSTFSZ XORWF BCF BSF BTFSC BTFSS BTG f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a fs, fd f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, b, a f, b, a f, b, a f, b, a f, d, a Add WREG and f Add WREG and Carry bit to f AND WREG with f Clear f Complement f Compare f with WREG, skip = Compare f with WREG, skip > Compare f with WREG, skip < Decrement f Decrement f, Skip if 0 Decrement f, Skip if Not 0 Increment f Increment f, Skip if 0 Increment f, Skip if Not 0 Inclusive OR WREG with f Move f Move fs (source) to 1st word fd (destination) 2nd word Move WREG to f Multiply WREG with f Negate f Rotate Left f through Carry Rotate Left f (No Carry) Rotate Right f through Carry Rotate Right f (No Carry) Set f Subtract f from WREG with borrow Subtract WREG from f Subtract WREG from f with borrow Swap nibbles in f Test f, skip if 0 Exclusive OR WREG with f Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set Bit Toggle f 1 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 (2 or 3) 1 1 1 1 (2 or 3) 1 (2 or 3) 1
0010 01da0 0010 0da 0001 01da 0110 101a 0001 11da 0110 001a 0110 010a 0110 000a 0000 01da 0010 11da 0100 11da 0010 10da 0011 11da 0100 10da 0001 00da 0101 00da 1100 ffff 1111 ffff 0110 111a 0000 001a 0110 110a 0011 01da 0100 01da 0011 00da 0100 00da 0110 100a 0101 01da 0101 0101 0011 0110 0001 11da 10da 10da 011a 10da bbba bbba bbba bbba bbba ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff
C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None None None C, DC, Z, OV, N C, Z, N Z, N C, Z, N Z, N None C, DC, Z, OV, N
1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1
1, 2 1, 2
1, 2
ffff C, DC, Z, OV, N ffff C, DC, Z, OV, N ffff None ffff None ffff Z, N ffff ffff ffff ffff ffff
1, 2 4 1, 2
BIT-ORIENTED FILE REGISTER OPERATIONS
1001 1000 1011 1010 0111
None None None None None
1, 2 1, 2 3, 4 3, 4 1, 2
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.
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PIC18FXX2
TABLE 20-2:
Mnemonic, Operands CONTROL OPERATIONS BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL CLRWDT DAW GOTO NOP NOP POP PUSH RCALL RESET RETFIE RETLW RETURN SLEEP n n n n n n n n n n, s -- -- n -- -- -- -- n s k s -- Branch if Carry Branch if Negative Branch if Not Carry Branch if Not Negative Branch if Not Overflow Branch if Not Zero Branch if Overflow Branch Unconditionally Branch if Zero Call subroutine1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to address1st word 2nd word No Operation No Operation Pop top of return stack (TOS) Push top of return stack (TOS) Relative Call Software device RESET Return from interrupt enable Return with literal in WREG Return from Subroutine Go into Standby mode 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 1 (2) 1 (2) 2 1 1 2 1 1 1 1 2 1 2 2 2 1
1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 0000 0000 0000 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 1100 0000 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 kkkk 0001 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s
PIC18FXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word Description Cycles MSb LSb Status Affected Notes
None None None None None None None None None None TO, PD C None
None None None None None All GIE/GIEH, PEIE/GIEL kkkk None 001s None 0011 TO, PD
4
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.
2002 Microchip Technology Inc.
DS39564B-page 215
PIC18FXX2
TABLE 20-2:
Mnemonic, Operands LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR MOVLB MOVLW MULLW RETLW SUBLW XORLW TBLRD* TBLRD*+ TBLRD*TBLRD+* TBLWT* TBLWT*+ TBLWT*TBLWT+* k k k f, k k k k k k k Add literal and WREG AND literal with WREG Inclusive OR literal with WREG Move literal (12-bit) 2nd word to FSRx 1st word Move literal to BSR<3:0> Move literal to WREG Multiply literal with WREG Return with literal in WREG Subtract WREG from literal Exclusive OR literal with WREG Table Read Table Read with post-increment Table Read with post-decrement Table Read with pre-increment Table Write Table Write with post-increment Table Write with post-decrement Table Write with pre-increment 1 1 1 2 1 1 1 2 1 1 2
0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk
PIC18FXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word Description Cycles MSb LSb Status Affected Notes
C, DC, Z, OV, N Z, N Z, N None None None None None C, DC, Z, OV, N Z, N None None None None None None None None
DATA MEMORY PROGRAM MEMORY OPERATIONS
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 1001 1010 1011 1100 1101 1110 1111
2 (5)
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 4: Some instructions are 2-word instructions. The second word of these instructions will be executed as a NOP, unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.
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PIC18FXX2
20.1
ADDLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
Instruction Set
ADD literal to W [ label ] ADDLW 0 k 255 (W) + k W N, OV, C, DC, Z
0000 1111 kkkk kkkk
ADDWF k Syntax: Operands:
ADD W to f [ label ] ADDWF 0 f 255 d [0,1] a [0,1] (W) + (f) dest N, OV, C, DC, Z
0010 01da ffff ffff
f [,d [,a]
Operation: Status Affected: Encoding: Description:
The contents of W are added to the 8-bit literal 'k' and the result is placed in W. 1 1 Q2
Read literal 'k'
ADDLW
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
0x15
Q4
Write to W
Add W to register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If `a' is 0, the Access Bank will be selected. If `a' is 1, the BSR is used. 1 1 Q2
Read register 'f'
ADDWF
Words: Cycles: Q Cycle Activity: Q1
Decode
Example:
W W = =
Before Instruction
0x10 0x25
Q3
Process Data
REG, 0, 0
Q4
Write to destination
After Instruction Example:
W REG W REG = = = =
Before Instruction
0x17 0xC2 0xD9 0xC2
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 217
PIC18FXX2
ADDWFC Syntax: Operands: ADD W and Carry bit to f [ label ] ADDWFC 0 f 255 d [0,1] a [0,1] (W) + (f) + (C) dest N,OV, C, DC, Z
0010 00da ffff ffff
ANDLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
AND literal with W [ label ] ANDLW 0 k 255 (W) .AND. k W N,Z
0000 1011 kkkk kkkk
f [,d [,a]
k
Operation: Status Affected: Encoding: Description:
Add W, the Carry Flag and data memory location 'f'. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed in data memory location 'f'. If `a' is 0, the Access Bank will be selected. If `a' is 1, the BSR will not be overridden. 1 1
The contents of W are ANDed with the 8-bit literal 'k'. The result is placed in W. 1 1 Q2
Read literal 'k'
ANDLW
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
0x5F
Q4
Write to W
Words: Cycles: Q Cycle Activity: Q1
Decode
Example: Q2
Read register 'f'
ADDWFC
Q3
Process Data
REG, 0, 1
Q4
Write to destination
Before Instruction
W W = = 0xA3 0x03
After Instruction
Example:
Carry bit = REG = W =
Before Instruction
1 0x02 0x4D 0 0x02 0x50
After Instruction
Carry bit = REG = W =
DS39564B-page 218
2002 Microchip Technology Inc.
PIC18FXX2
ANDWF Syntax: Operands: AND W with f [ label ] ANDWF 0 f 255 d [0,1] a [0,1] (W) .AND. (f) dest N,Z
0001 01da ffff ffff
BC f [,d [,a] Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Carry [ label ] BC n -128 n 127 if carry bit is '1' (PC) + 2 + 2n PC None
1110 0010 nnnn nnnn
Operation: Status Affected: Encoding: Description:
The contents of W are AND'ed with register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If `a' is 0, the Access Bank will be selected. If `a' is 1, the BSR will not be overridden (default). 1 1 Q2
Read register 'f'
ANDWF
If the Carry bit is '1', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
Words: Cycles: Q Cycle Activity: Q1
Decode
Words: Cycles: Q3
Process Data
REG, 0, 0
Q4
Write to destination
Q Cycle Activity: If Jump: Q1
Decode No operation
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
Example:
W REG W REG = = = =
Before Instruction
0x17 0xC2 0x02 0xC2
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BC 5
Q4
No operation
After Instruction
Example:
PC
Before Instruction
= = = = = address (HERE) 1; address (HERE+12) 0; address (HERE+2)
After Instruction
If Carry PC If Carry PC
2002 Microchip Technology Inc.
DS39564B-page 219
PIC18FXX2
BCF Syntax: Operands: Bit Clear f [ label ] BCF 0 f 255 0b7 a [0,1] 0 f None
1001 bbba ffff ffff
BN f,b[,a] Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Negative [ label ] BN n -128 n 127 if negative bit is '1' (PC) + 2 + 2n PC None
1110 0110 nnnn nnnn
Operation: Status Affected: Encoding: Description:
Bit 'b' in register 'f' is cleared. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
BCF
Words: Cycles: Q Cycle Activity: Q1
Decode
If the Negative bit is '1', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
Words: Cycles: Q3
Process Data
FLAG_REG,
Q4
Write register 'f'
7, 0
Q Cycle Activity: If Jump: Q1
Decode
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
Example:
Before Instruction
FLAG_REG = 0xC7
No operation
After Instruction
FLAG_REG = 0x47
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BN Jump
Q4
No operation
Example:
PC
Before Instruction
= = = = = address (HERE) 1; address (Jump) 0; address (HERE+2)
After Instruction
If Negative PC If Negative PC
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2002 Microchip Technology Inc.
PIC18FXX2
BNC Syntax: Operands: Operation: Status Affected: Encoding: Description: Branch if Not Carry [ label ] BNC -128 n 127 if carry bit is '0' (PC) + 2 + 2n PC None
1110 0011 nnnn nnnn
BNN Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Not Negative [ label ] BNN -128 n 127 if negative bit is '0' (PC) + 2 + 2n PC None
1110 0111 nnnn nnnn
n
n
If the Carry bit is '0', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
If the Negative bit is '0', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
Words: Cycles: Q Cycle Activity: If Jump: Q1
Decode No operation
Words: Cycles: Q Cycle Activity: If Jump: Q1
Decode No operation
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BNC Jump
Q4
No operation
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BNN Jump
Q4
No operation
Example:
PC
Example:
PC
Before Instruction
= = = = = address (HERE) 0; address (Jump) 1; address (HERE+2)
Before Instruction
= = = = = address (HERE) 0; address (Jump) 1; address (HERE+2)
After Instruction
If Carry PC If Carry PC
After Instruction
If Negative PC If Negative PC
2002 Microchip Technology Inc.
DS39564B-page 221
PIC18FXX2
BNOV Syntax: Operands: Operation: Status Affected: Encoding: Description: Branch if Not Overflow [ label ] BNOV -128 n 127 if overflow bit is '0' (PC) + 2 + 2n PC None
1110 0101 nnnn nnnn
BNZ Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Not Zero [ label ] BNZ -128 n 127 if zero bit is '0' (PC) + 2 + 2n PC None
1110 0001 nnnn nnnn
n
n
If the Overflow bit is '0', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
If the Zero bit is '0', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
Words: Cycles: Q Cycle Activity: If Jump: Q1
Decode No operation
Words: Cycles: Q Cycle Activity: If Jump: Q1
Decode No operation
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BNOV Jump
Q4
No operation
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BNZ Jump
Q4
No operation
Example:
PC
Example:
PC
Before Instruction
= = = = = address (HERE) 0; address (Jump) 1; address (HERE+2)
Before Instruction
= = = = = address (HERE) 0; address (Jump) 1; address (HERE+2)
After Instruction
If Overflow PC If Overflow PC
After Instruction
If Zero PC If Zero PC
DS39564B-page 222
2002 Microchip Technology Inc.
PIC18FXX2
BRA Syntax: Operands: Operation: Status Affected: Encoding: Description: Unconditional Branch [ label ] BRA n -1024 n 1023 (PC) + 2 + 2n PC None
1101 0nnn nnnn nnnn
BSF Syntax: Operands:
Bit Set f [ label ] BSF 0 f 255 0b7 a [0,1] 1 f None
1000 bbba ffff ffff
f,b[,a]
Operation: Status Affected: Encoding: Description:
Add the 2's complement number '2n' to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is a two-cycle instruction. 1 2 Q2
Read literal 'n' No operation
Words: Cycles: Q Cycle Activity: Q1
Decode No operation
Bit 'b' in register 'f' is set. If `a' is 0 Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value. 1 1 Q2
Read register 'f'
BSF
Words: Cycles: Q3
Process Data No operation
Q4
Write to PC No operation
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write register 'f'
Example: Example:
PC
HERE BRA Jump
FLAG_REG, 7, 1
Before Instruction
FLAG_REG = = 0x0A 0x8A
Before Instruction
= = address (HERE) address (Jump)
After Instruction
FLAG_REG
After Instruction
PC
2002 Microchip Technology Inc.
DS39564B-page 223
PIC18FXX2
BTFSC Syntax: Operands: Bit Test File, Skip if Clear [ label ] BTFSC f,b[,a] 0 f 255 0b7 a [0,1] skip if (f) = 0 None
1011 bbba ffff ffff
BTFSS Syntax: Operands:
Bit Test File, Skip if Set [ label ] BTFSS f,b[,a] 0 f 255 0b7 a [0,1] skip if (f) = 1 None
1010 bbba ffff ffff
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
If bit 'b' in register 'f' is 0, then the next instruction is skipped. If bit 'b' is 0, then the next instruction fetched during the current instruction execution is discarded, and a NOP is executed instead, making this a twocycle instruction. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
If bit 'b' in register 'f' is 1, then the next instruction is skipped. If bit 'b' is 1, then the next instruction fetched during the current instruction execution, is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q3
Process Data
Words: Cycles:
Words: Cycles:
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
No operation
Q Cycle Activity: Q1
Decode
Q2
Read register 'f'
Q4
No operation
If skip: Q1
No operation
If skip: Q2
No operation
Q3
No operation
Q4
No operation
Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE FALSE TRUE
Q4
No operation No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE FALSE TRUE
Q4
No operation No operation
No operation No operation
BTFSC : :
No operation No operation
BTFSS : :
Example:
FLAG, 1, 0
Example:
FLAG, 1, 0
Before Instruction
PC = = = = = address (HERE) 0; address (TRUE) 1; address (FALSE)
Before Instruction
PC = = = = = address (HERE) 0; address (FALSE) 1; address (TRUE)
After Instruction
If FLAG<1> PC If FLAG<1> PC
After Instruction
If FLAG<1> PC If FLAG<1> PC
DS39564B-page 224
2002 Microchip Technology Inc.
PIC18FXX2
BTG Syntax: Operands: Bit Toggle f [ label ] BTG f,b[,a] 0 f 255 0b7 a [0,1] (f) f None
0111 bbba ffff ffff
BOV Syntax: Operands: Operation: Status Affected: Encoding: Description:
Branch if Overflow [ label ] BOV -128 n 127 if overflow bit is '1' (PC) + 2 + 2n PC None
1110 0100 nnnn nnnn
n
Operation: Status Affected: Encoding: Description:
Bit 'b' in data memory location 'f' is inverted. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
BTG
Words: Cycles: Q Cycle Activity: Q1
Decode
If the Overflow bit is '1', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
Words: Cycles: Q3
Process Data
PORTC, 4, 0
Q4
Write register 'f'
Q Cycle Activity: If Jump: Q1
Decode
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
Example:
PORTC PORTC = =
Before Instruction:
0111 0101 [0x75] 0110 0101 [0x65]
No operation
After Instruction:
If No Jump: Q1
Decode
Q2
Read literal 'n'
HERE
Q3
Process Data
BOV Jump
Q4
No operation
Example:
PC
Before Instruction
= = = = = address (HERE) 1; address (Jump) 0; address (HERE+2)
After Instruction
If Overflow PC If Overflow PC
2002 Microchip Technology Inc.
DS39564B-page 225
PIC18FXX2
BZ Syntax: Operands: Operation: Status Affected: Encoding: Description: Branch if Zero [ label ] BZ n -128 n 127 if Zero bit is '1' (PC) + 2 + 2n PC None
1110 0000 nnnn nnnn
CALL Syntax: Operands: Operation:
Subroutine Call [ label ] CALL k [,s] 0 k 1048575 s [0,1] (PC) + 4 TOS, k PC<20:1>, if s = 1 (W) WS, (STATUS) STATUSS, (BSR) BSRS None
1110 1111 110s k19kkk k7kkk kkkk kkkk0 kkkk8
If the Zero bit is '1', then the program will branch. The 2's complement number '2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is then a two-cycle instruction. 1 1(2)
Status Affected: Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) Description:
Words: Cycles: Q Cycle Activity: If Jump: Q1
Decode No operation
Q2
Read literal 'n' No operation
Q3
Process Data No operation
Q4
Write to PC No operation
Subroutine call of entire 2 Mbyte memory range. First, return address (PC+ 4) is pushed onto the return stack. If 's' = 1, the W, STATUS and BSR registers are also pushed into their respective shadow registers, WS, STATUSS and BSRS. If 's' = 0, no update occurs (default). Then, the 20-bit value 'k' is loaded into PC<20:1>. CALL is a two-cycle instruction. 2 2 Q2
Read literal 'k'<7:0>, No operation
HERE
If No Jump: Q1
Decode
Words: Q2
Read literal 'n'
HERE
Q3
Process Data
BZ Jump
Q4
No operation
Cycles: Q Cycle Activity: Q1
Decode
Q3
Push PC to stack No operation
CALL
Q4
Read literal 'k'<19:8>, Write to PC No operation
Example:
PC
Before Instruction
= = = = = address (HERE) 1; address (Jump) 0; address (HERE+2)
After Instruction
If Zero PC If Zero PC
No operation
Example:
PC =
THERE,1
Before Instruction
address (HERE) address (THERE) address (HERE + 4) W BSR STATUS
After Instruction
PC = TOS = WS = BSRS = STATUSS=
DS39564B-page 226
2002 Microchip Technology Inc.
PIC18FXX2
CLRF Syntax: Operands: Operation: Status Affected: Encoding: Description: Clear f [ label ] CLRF 0 f 255 a [0,1] 000h f 1Z Z
0110 101a ffff ffff
CLRWDT f [,a] Syntax: Operands: Operation:
Clear Watchdog Timer [ label ] CLRWDT None 000h WDT, 000h WDT postscaler, 1 TO, 1 PD TO, PD
0000 0000 0000 0100
Status Affected: Encoding: Description:
Clears the contents of the specified register. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
CLRF
CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits TO and PD are set. 1 1 Q2
No operation
CLRWDT
Words: Cycles: Q Cycle Activity: Q1
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
No operation
Q3
Process Data
FLAG_REG,1
Q4
Write register 'f'
Decode
Example: Example: Before Instruction
FLAG_REG = = 0x5A 0x00
Before Instruction
WDT Counter = = = = = ? 0x00 0 1 1
After Instruction
WDT Counter WDT Postscaler
After Instruction
FLAG_REG
TO PD
2002 Microchip Technology Inc.
DS39564B-page 227
PIC18FXX2
COMF Syntax: Operands: Complement f [ label ] COMF 0 f 255 d [0,1] a [0,1] ( f ) dest N, Z
0001 11da ffff ffff
CPFSEQ f [,d [,a] Syntax: Operands: Operation:
Compare f with W, skip if f = W [ label ] CPFSEQ 0 f 255 a [0,1] (f) - (W), skip if (f) = (W) (unsigned comparison) None
0110 001a ffff ffff
f [,a]
Operation: Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
The contents of register 'f' are complemented. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
COMF
Words: Cycles: Q Cycle Activity: Q1
Decode
Compares the contents of data memory location 'f' to the contents of W by performing an unsigned subtraction. If 'f' = W, then the fetched instruction is discarded and a NOP is executed instead, making this a twocycle instruction. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
Q3
Process Data
REG, 0, 0
Q4
Write to destination
Words: Cycles:
Example:
REG REG W = = =
Before Instruction
0x13 0x13 0xEC
After Instruction
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE NEQUAL EQUAL
Q4
No operation No operation
No operation No operation
Example:
CPFSEQ REG, 0 : : HERE ? ?
Before Instruction
PC Address W REG = = = = = =
After Instruction
If REG PC If REG PC W; Address (EQUAL) W; Address (NEQUAL)
DS39564B-page 228
2002 Microchip Technology Inc.
PIC18FXX2
CPFSGT Syntax: Operands: Operation: Compare f with W, skip if f > W [ label ] CPFSGT 0 f 255 a [0,1] (f) - (W), skip if (f) > (W) (unsigned comparison) None
0110 010a ffff ffff
CPFSLT Syntax: Operands: Operation:
Compare f with W, skip if f < W [ label ] CPFSLT 0 f 255 a [0,1] (f) - (W), skip if (f) < (W) (unsigned comparison) None
0110 000a ffff ffff
f [,a]
f [,a]
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Compares the contents of data memory location 'f' to the contents of the W by performing an unsigned subtraction. If the contents of 'f' are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
Compares the contents of data memory location 'f' to the contents of W by performing an unsigned subtraction. If the contents of 'f' are less than the contents of W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is 0, the Access Bank will be selected. If 'a' is 1, the BSR will not be overridden (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
Words: Cycles:
Words: Cycles:
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
No operation
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE NLESS LESS
Q4
No operation No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE NGREATER GREATER
Q4
No operation No operation
No operation No operation
No operation No operation
Example:
Example:
CPFSGT REG, 0 : :
CPFSLT REG, 1 : :
Before Instruction
PC W = = < = = Address (HERE) ? W; Address (LESS) W; Address (NLESS)
Before Instruction
PC W = =
> = =
Address (HERE) ? W; Address (GREATER) W; Address (NGREATER)
After Instruction
If REG PC If REG PC
After Instruction
If REG PC If REG PC
2002 Microchip Technology Inc.
DS39564B-page 229
PIC18FXX2
DAW Syntax: Operands: Operation: Decimal Adjust W Register [ label ] DAW None If [W<3:0> >9] or [DC = 1] then (W<3:0>) + 6 W<3:0>; else (W<3:0>) W<3:0>; If [W<7:4> >9] or [C = 1] then (W<7:4>) + 6 W<7:4>; else (W<7:4>) W<7:4>; Status Affected: Encoding: Description: C
0000 0000 0000 0111
DECF Syntax: Operands:
Decrement f [ label ] DECF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) - 1 dest C, DC, N, OV, Z
0000 01da ffff ffff
Operation: Status Affected: Encoding: Description:
DAW adjusts the eight-bit value in W, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. 1 1 Q2
Read register W
DAW
Decrement register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
DECF
Words: Cycles: Q Cycle Activity: Q1
Decode
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
CNT, 1, 0
Q4
Write to destination
Q3
Process Data
Q4
Write W
Example:
CNT Z CNT Z = = = =
Example1:
W C DC W C DC = = = = = =
Before Instruction
0x01 0 0x00 1
Before Instruction
0xA5 0 0 0x05 1 0
After Instruction
After Instruction
Example 2: Before Instruction
W C DC W C DC = = = = = = 0xCE 0 0 0x34 1 0
After Instruction
DS39564B-page 230
2002 Microchip Technology Inc.
PIC18FXX2
DECFSZ Syntax: Operands: Decrement f, skip if 0 [ label ] DECFSZ f [,d [,a]] 0 f 255 d [0,1] a [0,1] (f) - 1 dest, skip if result = 0 None
0010 11da ffff ffff
DCFSNZ Syntax: Operands:
Decrement f, skip if not 0 [ label ] DCFSNZ 0 f 255 d [0,1] a [0,1] (f) - 1 dest, skip if result 0 None
0100 11da ffff ffff
f [,d [,a]
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
The contents of register 'f' are decremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If the result is 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a two-cycle instruction. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
The contents of register 'f' are decremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If the result is not 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a twocycle instruction. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
Words: Cycles:
Words: Cycles:
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write to destination
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write to destination
If skip: Q1
No operation
If skip: Q2
No operation
Q3
No operation
Q4
No operation
Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE CONTINUE
Q4
No operation No operation
CNT, 1, 1 LOOP
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE ZERO NZERO
Q4
No operation No operation
No operation No operation
DECFSZ GOTO
No operation No operation
DCFSNZ : :
Example:
Example:
TEMP, 1, 0
Before Instruction
PC CNT If CNT PC If CNT PC = = = = = Address (HERE) CNT - 1 0; Address (CONTINUE) 0; Address (HERE+2)
Before Instruction
TEMP = = = = = ? TEMP - 1, 0; Address (ZERO) 0; Address (NZERO)
After Instruction
After Instruction
TEMP If TEMP PC If TEMP PC
2002 Microchip Technology Inc.
DS39564B-page 231
PIC18FXX2
GOTO Syntax: Operands: Operation: Status Affected: Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) Description: Unconditional Branch [ label ] GOTO k 0 k 1048575 k PC<20:1> None
1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8
INCF Syntax: Operands:
Increment f [ label ] INCF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) + 1 dest C, DC, N, OV, Z
0010 10da ffff ffff
Operation: Status Affected: Encoding: Description:
GOTO allows an unconditional branch anywhere within entire 2 Mbyte memory range. The 20-bit value 'k' is loaded into PC<20:1>. GOTO is always a two-cycle instruction. 2 2
Words: Cycles: Q Cycle Activity: Q1
Decode
The contents of register 'f' are incremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
INCF
Words: Q2
Read literal 'k'<7:0>, No operation
Q3
No operation No operation
Q4
Read literal 'k'<19:8>, Write to PC No operation
Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
CNT, 1, 0
Q4
Write to destination
No operation
Example:
PC =
GOTO THERE
Example:
CNT Z C DC CNT Z C DC = = = = = = = =
After Instruction
Address (THERE)
Before Instruction
0xFF 0 ? ? 0x00 1 1 1
After Instruction
DS39564B-page 232
2002 Microchip Technology Inc.
PIC18FXX2
INCFSZ Syntax: Operands: Increment f, skip if 0 [ label ] INCFSZ f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) + 1 dest, skip if result = 0 None
0011 11da ffff ffff
INFSNZ Syntax: Operands:
Increment f, skip if not 0 [ label ] INFSNZ f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) + 1 dest, skip if result 0 None
0100 10da ffff ffff
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
The contents of register 'f' are incremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f'. (default) If the result is 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a two-cycle instruction. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
The contents of register 'f' are incremented. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If the result is not 0, the next instruction, which is already fetched, is discarded, and a NOP is executed instead, making it a twocycle instruction. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
Words: Cycles:
Words: Cycles:
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write to destination
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write to destination
If skip: Q1
No operation
If skip: Q2
No operation
Q3
No operation
Q4
No operation
Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE NZERO ZERO
Q4
No operation No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE ZERO NZERO
Q4
No operation No operation
No operation No operation
INCFSZ : :
No operation No operation
INFSNZ
Example:
CNT, 1, 0
Example:
REG, 1, 0
Before Instruction
PC CNT If CNT PC If CNT PC = = = = = Address (HERE) CNT + 1 0; Address (ZERO) 0; Address (NZERO)
Before Instruction
PC REG If REG PC If REG PC = = Address (HERE) REG + 1 0; Address (NZERO) 0; Address (ZERO)
After Instruction
After Instruction
= = =
2002 Microchip Technology Inc.
DS39564B-page 233
PIC18FXX2
IORLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Inclusive OR literal with W [ label ] IORLW k 0 k 255 (W) .OR. k W N, Z
0000 1001 kkkk kkkk
IORWF Syntax: Operands:
Inclusive OR W with f [ label ] IORWF f [,d [,a] 0 f 255 d [0,1] a [0,1] (W) .OR. (f) dest N, Z
0001 00da ffff ffff
Operation: Status Affected: Encoding: Description:
The contents of W are OR'ed with the eight-bit literal 'k'. The result is placed in W. 1 1 Q2
Read literal 'k'
IORLW
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
0x35
Q4
Write to W
Inclusive OR W with register 'f'. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
IORWF
Words: Example:
W W = =
Cycles: Q Cycle Activity: Q1
Decode
Before Instruction
0x9A 0xBF
Q3
Process Data
RESULT, 0, 1
Q4
Write to destination
After Instruction
Example:
RESULT = W =
Before Instruction
0x13 0x91 0x13 0x93
After Instruction
RESULT = W =
DS39564B-page 234
2002 Microchip Technology Inc.
PIC18FXX2
LFSR Syntax: Operands: Operation: Status Affected: Encoding: Description: Load FSR [ label ] LFSR f,k 0f2 0 k 4095 k FSRf None
1110 1111 1110 0000 00ff k7kkk k11kkk kkkk
MOVF Syntax: Operands:
Move f [ label ] MOVF f [,d [,a] 0 f 255 d [0,1] a [0,1] f dest N, Z
0101 00da ffff ffff
Operation: Status Affected: Encoding: Description:
The 12-bit literal 'k' is loaded into the file select register pointed to by 'f'. 2 2 Q2
Read literal 'k' MSB
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write literal 'k' MSB to FSRfH Write literal 'k' to FSRfL
The contents of register 'f' are moved to a destination dependent upon the status of 'd'. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). Location 'f' can be anywhere in the 256 byte bank. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
MOVF
Decode
Read literal 'k' LSB
Process Data
Words: Cycles: Q Cycle Activity: Q1
Decode
Example:
FSR2H FSR2L
LFSR 2, 0x3AB
After Instruction
= = 0x03 0xAB
Q3
Process Data
REG, 0, 0
Q4
Write W
Example:
REG W
Before Instruction
= = = = 0x22 0xFF 0x22 0x22
After Instruction
REG W
2002 Microchip Technology Inc.
DS39564B-page 235
PIC18FXX2
MOVFF Syntax: Operands: Operation: Status Affected: Encoding: 1st word (source) 2nd word (destin.) Description: Move f to f [ label ] MOVFF fs,fd 0 fs 4095 0 fd 4095 (fs) fd None
1100 1111 ffff ffff ffff ffff ffffs ffffd
MOVLB Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Move literal to low nibble in BSR [ label ] k BSR None
0000 0001 kkkk kkkk
MOVLB k
0 k 255
The 8-bit literal 'k' is loaded into the Bank Select Register (BSR). 1 1 Q2
Read literal 'k'
The contents of source register 'fs' are moved to destination register 'fd'. Location of source 'fs' can be anywhere in the 4096 byte data space (000h to FFFh), and location of destination 'fd' can also be anywhere from 000h to FFFh. Either source or destination can be W (a useful special situation). MOVFF is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). The MOVFF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. Note: The MOVFF instruction should not be used to modify interrupt settings while any interrupt is enabled. See Section 8.0 for more information.
Q3
Process Data
Q4
Write literal 'k' to BSR
Example:
MOVLB
5
Before Instruction
BSR register = = 0x02 0x05
After Instruction
BSR register
Words: Cycles: Q Cycle Activity: Q1
Decode
2 2 (3) Q2
Read register 'f' (src) No operation No dummy read
Q3
Process Data No operation
Q4
No operation Write register 'f' (dest)
Decode
Example:
REG1 REG2
MOVFF
REG1, REG2
Before Instruction
= = = = 0x33 0x11 0x33, 0x33
After Instruction
REG1 REG2
DS39564B-page 236
2002 Microchip Technology Inc.
PIC18FXX2
MOVLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Move literal to W [ label ] kW None
0000 1110 kkkk kkkk
MOVWF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Move W to f [ label ] MOVWF f [,a] 0 f 255 a [0,1] (W) f None
0110 111a ffff ffff
MOVLW k
0 k 255
The eight-bit literal 'k' is loaded into W. 1 1 Q2
Read literal 'k'
MOVLW
Q3
Process Data
0x5A
Q4
Write to W
Move data from W to register 'f'. Location 'f' can be anywhere in the 256 byte bank. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
MOVWF
Words: Cycles: Q Cycle Activity: Q1
Decode
Example:
W =
After Instruction
0x5A
Q3
Process Data
REG, 0
Q4
Write register 'f'
Example:
W REG W REG = = = =
Before Instruction
0x4F 0xFF 0x4F 0x4F
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 237
PIC18FXX2
MULLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Multiply Literal with W [ label ] MULLW k 0 k 255 (W) x k PRODH:PRODL None
0000 1101 kkkk kkkk
MULWF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Multiply W with f [ label ] MULWF f [,a] 0 f 255 a [0,1] (W) x (f) PRODH:PRODL None
0000 001a ffff ffff
An unsigned multiplication is carried out between the contents of W and the 8-bit literal 'k'. The 16-bit result is placed in PRODH:PRODL register pair. PRODH contains the high byte. W is unchanged. None of the status flags are affected. Note that neither overflow nor carry is possible in this operation. A zero result is possible but not detected. 1 1 Q2
Read literal 'k'
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write registers PRODH: PRODL
An unsigned multiplication is carried out between the contents of W and the register file location 'f'. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both W and 'f' are unchanged. None of the status flags are affected. Note that neither overflow nor carry is possible in this operation. A zero result is possible but not detected. If `a' is 0, the Access Bank will be selected, overriding the BSR value. If `a' = 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
Example:
W PRODH PRODL
MULLW
0xC4
Q3
Process Data
Q4
Write registers PRODH: PRODL
Before Instruction
= = = = = = 0xE2 ? ? 0xE2 0xAD 0x08
After Instruction
W PRODH PRODL
Example:
W REG PRODH PRODL
MULWF
REG, 1
Before Instruction
= = = = = = = = 0xC4 0xB5 ? ? 0xC4 0xB5 0x8A 0x94
After Instruction
W REG PRODH PRODL
DS39564B-page 238
2002 Microchip Technology Inc.
PIC18FXX2
NEGF Syntax: Operands: Operation: Status Affected: Encoding: Description: Negate f [ label ] NEGF f [,a] 0 f 255 a [0,1] (f)+1f N, OV, C, DC, Z
0110 110a ffff ffff
NOP Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
No Operation [ label ] None No operation None
0000 1111 0000 xxxx 0000 xxxx 0000 xxxx
NOP
Location `f' is negated using two's complement. The result is placed in the data memory location 'f'. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value. 1 1 Q2
Read register 'f'
NEGF
No operation. 1 1 Q2
No operation
Q3
No operation
Q4
No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
Example: Q3
Process Data
REG, 1
Q4
Write register 'f'
None.
Example:
REG REG = =
Before Instruction
0011 1010 [0x3A] 1100 0110 [0xC6]
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 239
PIC18FXX2
POP Syntax: Operands: Operation: Status Affected: Encoding: Description: Pop Top of Return Stack [ label ] None (TOS) bit bucket None
0000 0000 0000 0110
PUSH Syntax: Operands: Operation: Status Affected: Encoding: Description:
Push Top of Return Stack [ label ] None (PC+2) TOS None
0000 0000 0000 0101
POP
PUSH
The TOS value is pulled off the return stack and is discarded. The TOS value then becomes the previous value that was pushed onto the return stack. This instruction is provided to enable the user to properly manage the return stack to incorporate a software stack. 1 1 Q2
No operation
POP GOTO
The PC+2 is pushed onto the top of the return stack. The previous TOS value is pushed down on the stack. This instruction allows to implement a software stack by modifying TOS, and then push it onto the return stack. 1 1 Q2
PUSH PC+2 onto return stack
PUSH
Words: Cycles: Q Cycle Activity: Q1
Decode
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
No operation
Q4
No operation
Q3
POP TOS value
Q4
No operation
Example: Example:
NEW
Before Instruction
TOS PC 0031A2h 014332h = = 00345Ah 000124h
Before Instruction
TOS Stack (1 level down) = =
After Instruction
PC TOS Stack (1 level down) = = = 000126h 000126h 00345Ah
After Instruction
TOS PC = = 014332h NEW
DS39564B-page 240
2002 Microchip Technology Inc.
PIC18FXX2
RCALL Syntax: Operands: Operation: Status Affected: Encoding: Description: Relative Call [ label ] RCALL -1024 n 1023 (PC) + 2 TOS, (PC) + 2 + 2n PC None
1101 1nnn nnnn nnnn
RESET n Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Reset [ label ] None Reset all registers and flags that are affected by a MCLR Reset. All
0000 0000 1111 1111
RESET
Subroutine call with a jump up to 1K from the current location. First, return address (PC+2) is pushed onto the stack. Then, add the 2's complement number '2n' to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC+2+2n. This instruction is a two-cycle instruction. 1 2 Q2
Read literal 'n' Push PC to stack
This instruction provides a way to execute a MCLR Reset in software. 1 1 Q2
Start reset
RESET
Q3
No operation
Q4
No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
Example:
Registers = Flags* =
After Instruction Q3
Process Data
Q4
Write to PC
Reset Value Reset Value
No operation
No operation
HERE
No operation
RCALL Jump
No operation
Example:
PC = PC = TOS =
Before Instruction
Address (HERE) Address (Jump) Address (HERE+2)
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 241
PIC18FXX2
RETFIE Syntax: Operands: Operation: Return from Interrupt [ label ] s [0,1] (TOS) PC, 1 GIE/GIEH or PEIE/GIEL, if s = 1 (WS) W, (STATUSS) STATUS, (BSRS) BSR, PCLATU, PCLATH are unchanged. GIE/GIEH, PEIE/GIEL.
0000 0000 0001 000s
RETLW Syntax: Operands: Operation:
Return Literal to W [ label ] RETLW k 0 k 255 k W, (TOS) PC, PCLATU, PCLATH are unchanged None
0000 1100 kkkk kkkk
RETFIE [s]
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Return from Interrupt. Stack is popped and Top-of-Stack (TOS) is loaded into the PC. Interrupts are enabled by setting either the high or low priority global interrupt enable bit. If `s' = 1, the contents of the shadow registers WS, STATUSS and BSRS are loaded into their corresponding registers, W, STATUS and BSR. If `s' = 0, no update of these registers occurs (default). 1 2 Q2
No operation
W is loaded with the eight-bit literal 'k'. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged. 1 2 Q2
Read literal 'k' No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data No operation
Q4
pop PC from stack, Write to W No operation
No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
Example:
CALL TABLE ; ; ; ; : TABLE ADDWF PCL ; RETLW k0 ; RETLW k1 ; : : RETLW kn ; W contains table offset value W now has table value
Q3
No operation
Q4
pop PC from stack Set GIEH or GIEL
No operation
No operation
RETFIE 1
No operation
No operation
W = offset Begin table
Example: After Interrupt
End of table
PC W BSR STATUS GIE/GIEH, PEIE/GIEL
= = = = =
TOS WS BSRS STATUSS 1
Before Instruction
W W = = 0x07 value of kn
After Instruction
DS39564B-page 242
2002 Microchip Technology Inc.
PIC18FXX2
RETURN Syntax: Operands: Operation: Return from Subroutine [ label ] s [0,1] (TOS) PC, if s = 1 (WS) W, (STATUSS) STATUS, (BSRS) BSR, PCLATU, PCLATH are unchanged None
0000 0000 0001 001s
RLCF Syntax: Operands:
Rotate Left f through Carry [ label ] RLCF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) dest, (f<7>) C, (C) dest<0> C, N, Z
0011 01da ffff ffff
RETURN [s]
Operation:
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter. If `s'= 1, the contents of the shadow registers WS, STATUSS and BSRS are loaded into their corresponding registers, W, STATUS and BSR. If `s' = 0, no update of these registers occurs (default). 1 2 Q2
No operation No operation
The contents of register 'f' are rotated one bit to the left through the Carry Flag. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is stored back in register 'f' (default). If `a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' = 1, then the bank will be selected as per the BSR value (default). C
register f
Words: Cycles: Q Cycle Activity: Q1
Decode No operation
Words: Q3
Process Data No operation
1 1 Q2
Read register 'f'
RLCF
Q4
pop PC from stack No operation
Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write to destination
Example: Example: After Interrupt
PC = TOS
RETURN
REG, 0, 0
Before Instruction
REG C REG W C = = = = =
1110 0110 0 1110 0110 1100 1100 1
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 243
PIC18FXX2
RLNCF Syntax: Operands: Rotate Left f (no carry) [ label ] RLNCF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) dest, (f<7>) dest<0> N, Z
0100 01da ffff ffff
RRCF Syntax: Operands:
Rotate Right f through Carry [ label ] RRCF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) dest, (f<0>) C, (C) dest<7> C, N, Z
0011 00da ffff ffff
Operation: Status Affected: Encoding: Description:
Operation:
Status Affected: Encoding: Description:
The contents of register 'f' are rotated one bit to the left. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is stored back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default).
register f
The contents of register 'f' are rotated one bit to the right through the Carry Flag. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If `a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). C
register f
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Words: Q2
Read register 'f'
RLNCF
1 1 Q2
Read register 'f'
RRCF
Q3
Process Data
Q4
Write to destination
Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
REG, 0, 0
Q4
Write to destination
Example:
REG REG = =
REG, 1, 0
Before Instruction
1010 1011 0101 0111
Example:
REG C REG W C = = = = =
After Instruction
Before Instruction
1110 0110 0 1110 0110 0111 0011 0
After Instruction
DS39564B-page 244
2002 Microchip Technology Inc.
PIC18FXX2
RRNCF Syntax: Operands: Rotate Right f (no carry) [ label ] RRNCF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f) dest, (f<0>) dest<7> N, Z
0100 00da ffff ffff
SETF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Set f [ label ] SETF 0 f 255 a [0,1] FFh f None
0110 100a ffff ffff
f [,a]
Operation: Status Affected: Encoding: Description:
The contents of register 'f' are rotated one bit to the right. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default).
register f
The contents of the specified register are set to FFh. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
SETF
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
REG,1
Q4
Write register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
RRNCF
Example: Q3
Process Data
REG, 1, 0
Before Instruction Q4
Write to destination REG = = 0x5A 0xFF
After Instruction
REG
Example 1:
REG REG = =
Before Instruction
1101 0111 1110 1011 RRNCF REG, 0, 0
After Instruction
Example 2:
W REG
W REG
Before Instruction
= = = = ? 1101 0111
1110 1011 1101 0111
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 245
PIC18FXX2
SLEEP Syntax: Operands: Operation: Enter SLEEP mode [ label ] SLEEP None 00h WDT, 0 WDT postscaler, 1 TO, 0 PD TO, PD
0000 0000 0000 0011
SUBFWB Syntax: Operands:
Subtract f from W with borrow [ label ] SUBFWB 0 f 255 d [0,1] a [0,1] (W) - (f) - (C) dest N, OV, C, DC, Z
0101 01da ffff ffff
f [,d [,a]
Operation: Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
The power-down status bit (PD) is cleared. The time-out status bit (TO) is set. Watchdog Timer and its postscaler are cleared. The processor is put into SLEEP mode with the oscillator stopped. 1 1 Q2
No operation
SLEEP
Words: Cycles: Q Cycle Activity: Q1
Decode
Subtract register 'f' and carry flag (borrow) from W (2's complement method). If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
SUBFWB
Words: Q3
Process Data
Q4
Go to sleep
Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
REG, 1, 0
Q4
Write to destination
Example:
TO = PD = TO = PD = ? ?
Before Instruction
Example 1:
REG W C REG W C Z N = = = = = = = =
Before Instruction
3 2 1 FF 2 0 0 1 ; result is negative
SUBFWB REG, 0, 0
After Instruction
1 0
After Instruction
If WDT causes wake-up, this bit is cleared.
Example 2:
REG W C REG W C Z N = = = = = = = =
Before Instruction
2 5 1 2 3 1 0 0
After Instruction
; result is positive
REG, 1, 0
Example 3:
REG W C REG W C Z N = = = = = = = =
SUBFWB
Before Instruction
1 2 0 0 2 1 1 0
After Instruction
; result is zero
DS39564B-page 246
2002 Microchip Technology Inc.
PIC18FXX2
SUBLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Subtract W from literal [ label ] SUBLW k 0 k 255 k - (W) W N, OV, C, DC, Z
0000 1000 kkkk kkkk
SUBWF Syntax: Operands:
Subtract W from f [ label ] SUBWF 0 f 255 d [0,1] a [0,1] (f) - (W) dest N, OV, C, DC, Z
0101 11da ffff ffff
f [,d [,a]
Operation: Status Affected: Encoding: Description:
W is subtracted from the eight-bit literal 'k'. The result is placed in W. 1 1 Q2
Read literal 'k'
SUBLW
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
0x02
Q4
Write to W
Subtract W from register 'f' (2's complement method). If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
SUBWF
Example 1:
W C W C Z N = = = = = =
Words: Cycles: Q Cycle Activity: Q1
Decode
Before Instruction
1 ? 1 1 0 0
SUBLW
After Instruction
; result is positive
Q3
Process Data
REG, 1, 0
Q4
Write to destination
Example 1:
0x02
Example 2:
W C W C Z N = = = = = =
Before Instruction
REG W C REG W C Z N = = = = = = = = 3 2 ? 1 2 1 0 0
SUBWF
Before Instruction
2 ? 0 1 1 0
SUBLW
After Instruction
After Instruction
; result is zero
; result is positive
Example 3:
W C W C Z N = = = = = =
0x02
Example 2:
REG W C REG W C Z N = = = = = = = =
REG, 0, 0
Before Instruction
3 ? FF ; (2's complement) 0 ; result is negative 0 1
Before Instruction
2 2 ? 2 0 1 1 0
SUBWF
After Instruction
After Instruction
; result is zero
Example 3:
REG W C REG W C Z N = = = = = = = =
REG, 1, 0
Before Instruction
1 2 ? FFh ;(2's complement) 2 0 ; result is negative 0 1
After Instruction
2002 Microchip Technology Inc.
DS39564B-page 247
PIC18FXX2
SUBWFB Syntax: Operands: Subtract W from f with Borrow [ label ] SUBWFB 0 f 255 d [0,1] a [0,1] (f) - (W) - (C) dest N, OV, C, DC, Z
0101 10da ffff ffff
SWAPF Syntax: Operands:
Swap f [ label ] SWAPF f [,d [,a] 0 f 255 d [0,1] a [0,1] (f<3:0>) dest<7:4>, (f<7:4>) dest<3:0> None
0011 10da ffff ffff
f [,d [,a]
Operation: Status Affected: Encoding: Description:
Operation: Status Affected: Encoding: Description:
Subtract W and the carry flag (borrow) from register 'f' (2's complement method). If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
SUBWFB
Words: Cycles: Q Cycle Activity: Q1
Decode
The upper and lower nibbles of register 'f' are exchanged. If 'd' is 0, the result is placed in W. If 'd' is 1, the result is placed in register 'f' (default). If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
SWAPF
Words: Cycles: Q3
Process Data
REG, 1, 0
Q4
Write to destination
Q Cycle Activity: Q1
Decode
Q3
Process Data
REG, 1, 0
Q4
Write to destination
Example 1:
REG W C REG W C Z N = = = = = = = =
Before Instruction
0x19 0x0D 1 0x0C 0x0D 1 0 0
(0001 1001) (0000 1101)
Example:
REG REG = =
Before Instruction
0x53 0x35
After Instruction
(0000 1011) (0000 1101)
After Instruction
; result is positive
Example 2:
REG W C REG W C Z N = = = = = = = =
SUBWFB REG, 0, 0
Before Instruction
0x1B 0x1A 0 0x1B 0x00 1 1 0
SUBWFB (0001 1011) (0001 1010)
After Instruction
(0001 1011)
; result is zero
REG, 1, 0
Example 3:
REG W C REG
W C Z N
Before Instruction
= = = = = = = = 0x03 0x0E 1 0xF5 0x0E 0 0 1
(0000 0011) (0000 1101)
After Instruction
(1111 0100) ; [2's comp] (0000 1101)
; result is negative
DS39564B-page 248
2002 Microchip Technology Inc.
PIC18FXX2
TBLRD Syntax: Operands: Operation: Table Read [ label ] None if TBLRD *, (Prog Mem (TBLPTR)) TABLAT; TBLPTR - No Change; if TBLRD *+, (Prog Mem (TBLPTR)) TABLAT; (TBLPTR) +1 TBLPTR; if TBLRD *-, (Prog Mem (TBLPTR)) TABLAT; (TBLPTR) -1 TBLPTR; if TBLRD +*, (TBLPTR) +1 TBLPTR; (Prog Mem (TBLPTR)) TABLAT;
0000 0000 0000 10nn nn=0 * =1 *+ =2 *=3 +*
TBLRD Example1:
Table Read (cont'd)
TBLRD *+ ;
TBLRD ( *; *+; *-; +*)
Before Instruction
TABLAT TBLPTR MEMORY(0x00A356) = = = = =
TBLRD +* ;
0x55 0x00A356 0x34 0x34 0x00A357
After Instruction
TABLAT TBLPTR
Example2:
Before Instruction
TABLAT TBLPTR MEMORY(0x01A357) MEMORY(0x01A358) = = = = = = 0xAA 0x01A357 0x12 0x34 0x34 0x01A358
Status Affected:None Encoding:
After Instruction
TABLAT TBLPTR
Description:
This instruction is used to read the contents of Program Memory (P.M.). To address the program memory, a pointer called Table Pointer (TBLPTR) is used. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2 Mbyte address range. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLRD instruction can modify the value of TBLPTR as follows: * no change * post-increment * post-decrement * pre-increment 1 2 Q2
No operation No operation (Read Program Memory)
Words: Cycles:
Q Cycle Activity: Q1
Decode No operation
Q3
No operation
Q4
No operation
No No operation operation (Write TABLAT)
2002 Microchip Technology Inc.
DS39564B-page 249
PIC18FXX2
TBLWT Syntax: Operands: Operation: Table Write [ label ] None if TBLWT*, (TABLAT) Holding Register; TBLPTR - No Change; if TBLWT*+, (TABLAT) Holding Register; (TBLPTR) +1 TBLPTR; if TBLWT*-, (TABLAT) Holding Register; (TBLPTR) -1 TBLPTR; if TBLWT+*, (TBLPTR) +1 TBLPTR; (TABLAT) Holding Register;
0000 0000 0000 11nn nn=0 * =1 *+ =2 *=3 +*
TBLWT Example1:
Table Write (Continued)
TBLWT *+;
TBLWT ( *; *+; *-; +*)
Before Instruction
TABLAT TBLPTR HOLDING REGISTER (0x00A356) TABLAT TBLPTR HOLDING REGISTER (0x00A356) = = = = = =
+*;
0x55 0x00A356 0xFF 0x55 0x00A357 0x55
After Instructions (table write completion)
Example 2:
TBLWT
Before Instruction
TABLAT TBLPTR HOLDING REGISTER (0x01389A) HOLDING REGISTER (0x01389B) TABLAT TBLPTR HOLDING REGISTER (0x01389A) HOLDING REGISTER (0x01389B) = = = = = = = = 0x34 0x01389A 0xFF 0xFF 0x34 0x01389B 0xFF 0x34
Status Affected: None Encoding:
After Instruction (table write completion)
Description:
This instruction uses the 3 LSbs of the TBLPTR to determine which of the 8 holding registers the TABLAT data is written to. The 8 holding registers are used to program the contents of Program Memory (P.M.). See Section 5.0 for information on writing to FLASH memory. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2 MBtye address range. The LSb of the TBLPTR selects which byte of the program memory location to access. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLWT instruction can modify the value of TBLPTR as follows: * no change * post-increment * post-decrement * pre-increment 1 2 Q3
No operation No operation
Words: Cycles:
Q Cycle Activity: Q1 Q2
Decode No operation No operation No operation (Read TABLAT)
Q4
No operation No operation (Write to Holding Register or Memory)
DS39564B-page 250
2002 Microchip Technology Inc.
PIC18FXX2
TSTFSZ Syntax: Operands: Operation: Status Affected: Encoding: Description: Test f, skip if 0 [ label ] TSTFSZ f [,a] 0 f 255 a [0,1] skip if f = 0 None
0110 011a ffff ffff
XORLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
Exclusive OR literal with W [ label ] XORLW k 0 k 255 (W) .XOR. k W N, Z
0000 1010 kkkk kkkk
If 'f' = 0, the next instruction, fetched during the current instruction execution, is discarded and a NOP is executed, making this a twocycle instruction. If 'a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q2
Read register 'f'
The contents of W are XORed with the 8-bit literal 'k'. The result is placed in W. 1 1 Q2
Read literal 'k'
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
Write to W
Words: Cycles:
Example:
W W = =
XORLW 0xAF
0xB5 0x1A
Before Instruction After Instruction
Q Cycle Activity: Q1
Decode
Q3
Process Data
Q4
No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip and followed by 2-word instruction: Q1 Q2 Q3
No operation No operation No operation No operation
HERE NZERO ZERO
Q4
No operation No operation
No operation No operation
TSTFSZ : :
Example:
CNT, 1
Before Instruction
PC = Address (HERE)
After Instruction
If CNT PC If CNT PC = = = 0x00, Address (ZERO) 0x00, Address (NZERO)
2002 Microchip Technology Inc.
DS39564B-page 251
PIC18FXX2
XORWF Syntax: Operands: Exclusive OR W with f [ label ] XORWF 0 f 255 d [0,1] a [0,1] (W) .XOR. (f) dest N, Z
0001 10da ffff ffff
f [,d [,a]
Operation: Status Affected: Encoding: Description:
Exclusive OR the contents of W with register 'f'. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in the register 'f' (default). If `a' is 0, the Access Bank will be selected, overriding the BSR value. If 'a' is 1, then the bank will be selected as per the BSR value (default). 1 1 Q2
Read register 'f'
XORWF
Words: Cycles: Q Cycle Activity: Q1
Decode
Q3
Process Data
REG, 1, 0
Q4
Write to destination
Example:
REG W REG W = = = =
Before Instruction
0xAF 0xB5 0x1A 0xB5
After Instruction
DS39564B-page 252
2002 Microchip Technology Inc.
PIC18FXX2
21.0 DEVELOPMENT SUPPORT
The MPLAB IDE allows you to: * Edit your source files (either assembly or `C') * One touch assemble (or compile) and download to PICmicro emulator and simulator tools (automatically updates all project information) * Debug using: - source files - absolute listing file - machine code The ability to use MPLAB IDE with multiple debugging tools allows users to easily switch from the costeffective simulator to a full-featured emulator with minimal retraining. The PICmicro(R) microcontrollers are supported with a full range of hardware and software development tools: * Integrated Development Environment - MPLAB(R) IDE Software * Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C17 and MPLAB C18 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian * Simulators - MPLAB SIM Software Simulator * Emulators - MPLAB ICE 2000 In-Circuit Emulator - ICEPICTM In-Circuit Emulator * In-Circuit Debugger - MPLAB ICD * Device Programmers - PRO MATE(R) II Universal Device Programmer - PICSTART(R) Plus Entry-Level Development Programmer * Low Cost Demonstration Boards - PICDEMTM 1 Demonstration Board - PICDEM 2 Demonstration Board - PICDEM 3 Demonstration Board - PICDEM 17 Demonstration Board - KEELOQ(R) Demonstration Board
21.2
MPASM Assembler
The MPASM assembler is a full-featured universal macro assembler for all PICmicro MCU's. The MPASM assembler has a command line interface and a Windows shell. It can be used as a stand-alone application on a Windows 3.x or greater system, or it can be used through MPLAB IDE. The MPASM assembler generates relocatable object files for the MPLINK object linker, Intel(R) standard HEX files, MAP files to detail memory usage and symbol reference, an absolute LST file that contains source lines and generated machine code, and a COD file for debugging. The MPASM assembler features include: * Integration into MPLAB IDE projects. * User-defined macros to streamline assembly code. * Conditional assembly for multi-purpose source files. * Directives that allow complete control over the assembly process.
21.1
MPLAB Integrated Development Environment Software
The MPLAB IDE software brings an ease of software development previously unseen in the 8-bit microcontroller market. The MPLAB IDE is a Windows(R) based application that contains: * An interface to debugging tools - simulator - programmer (sold separately) - emulator (sold separately) - in-circuit debugger (sold separately) * A full-featured editor * A project manager * Customizable toolbar and key mapping * A status bar * On-line help
21.3
MPLAB C17 and MPLAB C18 C Compilers
The MPLAB C17 and MPLAB C18 Code Development Systems are complete ANSI `C' compilers for Microchip's PIC17CXXX and PIC18CXXX family of microcontrollers, respectively. These compilers provide powerful integration capabilities and ease of use not found with other compilers. For easier source level debugging, the compilers provide symbol information that is compatible with the MPLAB IDE memory display.
2002 Microchip Technology Inc.
DS39564B-page 253
PIC18FXX2
21.4 MPLINK Object Linker/ MPLIB Object Librarian 21.6 MPLAB ICE High Performance Universal In-Circuit Emulator with MPLAB IDE
The MPLINK object linker combines relocatable objects created by the MPASM assembler and the MPLAB C17 and MPLAB C18 C compilers. It can also link relocatable objects from pre-compiled libraries, using directives from a linker script. The MPLIB object librarian is a librarian for precompiled code to be used with the MPLINK object linker. When a routine from a library is called from another source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The MPLIB object librarian manages the creation and modification of library files. The MPLINK object linker features include: * Integration with MPASM assembler and MPLAB C17 and MPLAB C18 C compilers. * Allows all memory areas to be defined as sections to provide link-time flexibility. The MPLIB object librarian features include: * Easier linking because single libraries can be included instead of many smaller files. * Helps keep code maintainable by grouping related modules together. * Allows libraries to be created and modules to be added, listed, replaced, deleted or extracted.
The MPLAB ICE universal in-circuit emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PICmicro microcontrollers (MCUs). Software control of the MPLAB ICE in-circuit emulator is provided by the MPLAB Integrated Development Environment (IDE), which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the MPLAB ICE in-circuit emulator allows expansion to support new PICmicro microcontrollers. The MPLAB ICE in-circuit emulator system has been designed as a real-time emulation system, with advanced features that are generally found on more expensive development tools. The PC platform and Microsoft(R) Windows environment were chosen to best make these features available to you, the end user.
21.7
ICEPIC In-Circuit Emulator
21.5
MPLAB SIM Software Simulator
The MPLAB SIM software simulator allows code development in a PC-hosted environment by simulating the PICmicro series microcontrollers on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a file, or user-defined key press, to any of the pins. The execution can be performed in single step, execute until break, or trace mode. The MPLAB SIM simulator fully supports symbolic debugging using the MPLAB C17 and the MPLAB C18 C compilers and the MPASM assembler. The software simulator offers the flexibility to develop and debug code outside of the laboratory environment, making it an excellent multiproject software development tool.
The ICEPIC low cost, in-circuit emulator is a solution for the Microchip Technology PIC16C5X, PIC16C6X, PIC16C7X and PIC16CXXX families of 8-bit OneTime-Programmable (OTP) microcontrollers. The modular system can support different subsets of PIC16C5X or PIC16CXXX products through the use of interchangeable personality modules, or daughter boards. The emulator is capable of emulating without target application circuitry being present.
DS39564B-page 254
2002 Microchip Technology Inc.
PIC18FXX2
21.8 MPLAB ICD In-Circuit Debugger
Microchip's In-Circuit Debugger, MPLAB ICD, is a powerful, low cost, run-time development tool. This tool is based on the FLASH PICmicro MCUs and can be used to develop for this and other PICmicro microcontrollers. The MPLAB ICD utilizes the in-circuit debugging capability built into the FLASH devices. This feature, along with Microchip's In-Circuit Serial ProgrammingTM protocol, offers cost-effective in-circuit FLASH debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by watching variables, single-stepping and setting break points. Running at full speed enables testing hardware in realtime.
21.11 PICDEM 1 Low Cost PICmicro Demonstration Board
The PICDEM 1 demonstration board is a simple board which demonstrates the capabilities of several of Microchip's microcontrollers. The microcontrollers supported are: PIC16C5X (PIC16C54 to PIC16C58A), PIC16C61, PIC16C62X, PIC16C71, PIC16C8X, PIC17C42, PIC17C43 and PIC17C44. All necessary hardware and software is included to run basic demo programs. The user can program the sample microcontrollers provided with the PICDEM 1 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer, and easily test firmware. The user can also connect the PICDEM 1 demonstration board to the MPLAB ICE incircuit emulator and download the firmware to the emulator for testing. A prototype area is available for the user to build some additional hardware and connect it to the microcontroller socket(s). Some of the features include an RS-232 interface, a potentiometer for simulated analog input, push button switches and eight LEDs connected to PORTB.
21.9
PRO MATE II Universal Device Programmer
The PRO MATE II universal device programmer is a full-featured programmer, capable of operating in stand-alone mode, as well as PC-hosted mode. The PRO MATE II device programmer is CE compliant. The PRO MATE II device programmer has programmable VDD and VPP supplies, which allow it to verify programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for instructions and error messages, keys to enter commands and a modular detachable socket assembly to support various package types. In stand-alone mode, the PRO MATE II device programmer can read, verify, or program PICmicro devices. It can also set code protection in this mode.
21.12 PICDEM 2 Low Cost PIC16CXX Demonstration Board
The PICDEM 2 demonstration board is a simple demonstration board that supports the PIC16C62, PIC16C64, PIC16C65, PIC16C73 and PIC16C74 microcontrollers. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample microcontrollers provided with the PICDEM 2 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer, and easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 2 demonstration board to test firmware. A prototype area has been provided to the user for adding additional hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push button switches, a potentiometer for simulated analog input, a serial EEPROM to demonstrate usage of the I2CTM bus and separate headers for connection to an LCD module and a keypad.
21.10 PICSTART Plus Entry Level Development Programmer
The PICSTART Plus development programmer is an easy-to-use, low cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus development programmer supports all PICmicro devices with up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus development programmer is CE compliant.
2002 Microchip Technology Inc.
DS39564B-page 255
PIC18FXX2
21.13 PICDEM 3 Low Cost PIC16CXXX Demonstration Board
The PICDEM 3 demonstration board is a simple demonstration board that supports the PIC16C923 and PIC16C924 in the PLCC package. It will also support future 44-pin PLCC microcontrollers with an LCD Module. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample microcontrollers provided with the PICDEM 3 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer with an adapter socket, and easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 3 demonstration board to test firmware. A prototype area has been provided to the user for adding hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push button switches, a potentiometer for simulated analog input, a thermistor and separate headers for connection to an external LCD module and a keypad. Also provided on the PICDEM 3 demonstration board is a LCD panel, with 4 commons and 12 segments, that is capable of displaying time, temperature and day of the week. The PICDEM 3 demonstration board provides an additional RS-232 interface and Windows software for showing the demultiplexed LCD signals on a PC. A simple serial interface allows the user to construct a hardware demultiplexer for the LCD signals.
21.14 PICDEM 17 Demonstration Board
The PICDEM 17 demonstration board is an evaluation board that demonstrates the capabilities of several Microchip microcontrollers, including PIC17C752, PIC17C756A, PIC17C762 and PIC17C766. All necessary hardware is included to run basic demo programs, which are supplied on a 3.5-inch disk. A programmed sample is included and the user may erase it and program it with the other sample programs using the PRO MATE II device programmer, or the PICSTART Plus development programmer, and easily debug and test the sample code. In addition, the PICDEM 17 demonstration board supports downloading of programs to and executing out of external FLASH memory on board. The PICDEM 17 demonstration board is also usable with the MPLAB ICE in-circuit emulator, or the PICMASTER emulator and all of the sample programs can be run and modified using either emulator. Additionally, a generous prototype area is available for user hardware.
21.15 KEELOQ Evaluation and Programming Tools
KEELOQ evaluation and programming tools support Microchip's HCS Secure Data Products. The HCS evaluation kit includes a LCD display to show changing codes, a decoder to decode transmissions and a programming interface to program test transmitters.
DS39564B-page 256
2002 Microchip Technology Inc.
24CXX/ 25CXX/ 93CXX
PIC14000
HCSXXX
PIC16C5X
PIC16C6X
PIC16C7X
PIC17C4X
PIC16F62X
PIC16C8X/ PIC16F8X
PIC16C7XX
PIC16F8XX
PIC16C9XX
PIC17C7XX
PIC18CXX2
PIC12CXXX
PIC16CXXX
PIC18FXXX
MCRFXXX
MCP2510
TABLE 21-1:
MPLAB(R) Integrated Development Environment
9
9
9
9
9
9
9
9
9
9
9
9
9
99
99
MPLAB(R) C17 C Compiler
Software Tools
MPLAB(R) C18 C Compiler
MPASMTM Assembler/ MPLINKTM Object Linker
9
9
Programmers Debugger Emulators
Demo Boards and Eval Kits
2002 Microchip Technology Inc.
999
999
99
**
99
99
99
99
99
99
99
99
99
99
99
99
MPLAB(R) ICE In-Circuit Emulator
ICEPICTM In-Circuit Emulator
9
* *
9
9
9
9
9
9
9
MPLAB(R) ICD In-Circuit Debugger
9
**
9
9
9
PICSTART(R) Plus Entry Level Development Programmer
9
**
9
9
9
9
9
9
9
9
9
9
9
9
9
9
PRO MATE(R) II Universal Device Programmer
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
PICDEMTM 1 Demonstration Board
9

9
9
9
9
DEVELOPMENT TOOLS FROM MICROCHIP
PICDEMTM 2 Demonstration Board
9
9
9
9
PICDEMTM 3 Demonstration Board
9
PICDEMTM 14A Demonstration Board
9
PICDEMTM 17 Demonstration Board
9
KEELOQ(R) Evaluation Kit
99
KEELOQ(R) Transponder Kit
microIDTM Programmer's Kit
99
125 kHz microIDTM Developer's Kit
125 kHz Anticollision microIDTM Developer's Kit
9
13.56 MHz Anticollision microIDTM Developer's Kit
9
PIC18FXX2
DS39564B-page 257
MCP2510 CAN Developer's Kit
* Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB(R) ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77. ** Contact Microchip Technology Inc. for availability date. Development tool is available on select devices.
9
PIC18FXX2
NOTES:
DS39564B-page 258
2002 Microchip Technology Inc.
PIC18FXX2
22.0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings () Ambient temperature under bias.............................................................................................................-55C to +125C Storage temperature .............................................................................................................................. -65C to +150C Voltage on any pin with respect to VSS (except VDD, MCLR, and RA4) ......................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V Voltage on RA4 with respect to Vss ............................................................................................................... 0V to +8.5V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... 20 mA Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. 20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk by PORTA, PORTB, and PORTE (Note 3) (combined) ...................................................200 mA Maximum current sourced by PORTA, PORTB, and PORTE (Note 3) (combined)..............................................200 mA Maximum current sunk by PORTC and PORTD (Note 3) (combined)..................................................................200 mA Maximum current sourced by PORTC and PORTD (Note 3) (combined).............................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - IOH} + {(VDD-VOH) x IOH} + (VOl x IOL) 2: Voltage spikes below VSS at the MCLR/VPP pin, inducing currents greater than 80 mA, may cause latchup. Thus, a series resistor of 50-100 should be used when applying a "low" level to the MCLR/VPP pin, rather than pulling this pin directly to VSS. 3: PORTD and PORTE not available on the PIC18F2X2 devices.
NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
2002 Microchip Technology Inc.
DS39564B-page 259
PIC18FXX2
FIGURE 22-1: PIC18FXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V 5.5V 5.0V PIC18FXXX 4.2V
Voltage
4.5V 4.0V 3.5V 3.0V 2.5V 2.0V
40 MHz
Frequency
FIGURE 22-2:
PIC18LFXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V 5.5V 5.0V PIC18LFXXX 4.2V
Voltage
4.5V 4.0V 3.5V 3.0V 2.5V 2.0V
4 MHz
40 MHz
Frequency
FMAX = (16.36 MHz/V) (VDDAPPMIN - 2.0V) + 4 MHz Note: VDDAPPMIN is the minimum voltage of the PICmicro(R) device in the application.
DS39564B-page 260
2002 Microchip Technology Inc.
PIC18FXX2
22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Min Typ Max Units Conditions
PIC18LFXX2 (Industrial) PIC18FXX2 (Industrial, Extended) Param Symbol No. VDD D001 D001 D002 D003 VDR VPOR Characteristic Supply Voltage PIC18LFXX2 PIC18FXX2 RAM Data Retention Voltage(1) VDD Start Voltage to ensure internal Power-on Reset signal VDD Rise Rate to ensure internal Power-on Reset signal PIC18LFXX2 BORV1:BORV0 = 11 BORV1:BORV0 = 10 BORV1:BORV0 = 01 BORV1:BORV0 = 00 D005 PIC18FXX2 BORV1:BORV0 = 1x BORV1:BORV0 = 01 BORV1:BORV0 = 00
2.0 4.2 1.5 --
-- -- -- --
5.5 5.5 -- 0.7
V V V V
HS, XT, RC and LP Osc mode
See Section 3.1 (Power-on Reset) for details
D004
SVDD
0.05
--
--
V/ms See Section 3.1 (Power-on Reset) for details
VBOR D005
Brown-out Reset Voltage 1.98 2.67 4.16 4.45 N.A. 4.16 4.45 -- -- -- -- -- -- -- 2.14 2.89 4.5 4.83 N.A. 4.5 4.83 V V V V V V V Not in operating voltage range of device 85C T 25C
Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The IBOR and ILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.
2002 Microchip Technology Inc.
DS39564B-page 261
PIC18FXX2
22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Min Typ Max Units Conditions
PIC18LFXX2 (Industrial) PIC18FXX2 (Industrial, Extended) Param Symbol No. IDD D010 Characteristic Supply Current(2,4) PIC18LFXX2
-- -- -- -- -- -- -- -- -- D010 PIC18FXX2 -- -- -- -- -- -- -- -- -- D010A D010A PIC18LFXX2 -- PIC18FXX2 -- --
.5 .5 1.2 .3 .3 1.5 .3 .3 .75 1.2 1.2 1.2 1.5 1.5 1.6 .75 .75 .8 14 40 50
1 1.25 2 1 1 3 1 1 3 1.5 2 3 3 4 4 2 3 3 30 70 100
mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA A A A
XT osc configuration VDD = 2.0V, +25C, FOSC = 4 MHz VDD = 2.0V, -40C to +85C, FOSC = 4 MHz VDD = 4.2V, -40C to +85C, FOSC = 4 MHz RC osc configuration VDD = 2.0V, +25C, FOSC = 4 MHz VDD = 2.0V, -40C to +85C, FOSC = 4 MHz VDD = 4.2V, -40C to +85C, FOSC = 4 MHz RCIO osc configuration VDD = 2.0V, +25C, FOSC = 4 MHz VDD = 2.0V, -40C to +85C, FOSC = 4 MHz VDD = 4.2V, -40C to +85C, FOSC = 4 MHz XT osc configuration VDD = 4.2V, +25C, FOSC = 4 MHz VDD = 4.2V, -40C to +85C, FOSC = 4 MHz VDD = 4.2V, -40C to +125C, FOSC = 4 MHz RC osc configuration VDD = 4.2V, +25C, FOSC = 4 MHz VDD = 4.2V, -40C to +85C, FOSC = 4 MHz VDD = 4.2V, -40C to +125C, FOSC = 4 MHz RCIO osc configuration VDD = 4.2V, +25C, FOSC = 4 MHz VDD = 4.2V, -40C to +85C, FOSC = 4 MHz VDD = 4.2V, -40C to +125C, FOSC = 4 MHz LP osc, FOSC = 32 kHz, WDT disabled VDD = 2.0V, -40C to +85C LP osc, FOSC = 32 kHz, WDT disabled VDD = 4.2V, -40C to +85C VDD = 4.2V, -40C to +125C
Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The IBOR and ILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.
DS39564B-page 262
2002 Microchip Technology Inc.
PIC18FXX2
22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Min Typ Max Units Conditions
PIC18LFXX2 (Industrial) PIC18FXX2 (Industrial, Extended) Param Symbol No. IDD D010C D010C D013 Characteristic
Supply Current(2,4) (Continued) PIC18LFXX2 -- PIC18FXX2 -- PIC18LFXX2 -- -- -- .6 10 15 10 15 15 -- -- .08 .1 3 .1 3 15 2 15 25 15 25 55 200 250 .9 4 10 .9 10 25 mA mA mA mA mA A A A A A A A A A 10 25 mA 10 25 mA EC, ECIO osc configurations VDD = 4.2V, -40C to +85C EC, ECIO osc configurations VDD = 4.2V, -40C to +125C HS osc configuration FOSC = 4 MHz, VDD = 2.0V FOSC = 25 MHz, VDD = 5.5V HS + PLL osc configurations FOSC = 10 MHz, VDD = 5.5V HS osc configuration FOSC = 25 MHz, VDD = 5.5V HS + PLL osc configurations FOSC = 10 MHz, VDD = 5.5V Timer1 osc configuration FOSC = 32 kHz, VDD = 2.0V Timer1 osc configuration FOSC = 32 kHz, VDD = 4.2V, -40C to +85C FOSC = 32 kHz, VDD = 4.2V, -40C to +125C VDD = 2.0V, +25C VDD = 2.0V, -40C to +85C VDD = 4.2V, -40C to +85C VDD = 4.2V, +25C VDD = 4.2V, -40C to +85C VDD = 4.2V, -40C to +125C
D013
PIC18FXX2 -- --
D014 D014
PIC18LFXX2 -- PIC18FXX2 -- -- IPD Power-down Current(3) PIC18LFXX2 -- -- -- -- -- --
D020
D020 D021B
PIC18FXX2
Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The IBOR and ILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.
2002 Microchip Technology Inc.
DS39564B-page 263
PIC18FXX2
22.1 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Min Typ Max Units Conditions
PIC18LFXX2 (Industrial) PIC18FXX2 (Industrial, Extended) Param Symbol No. D022 IWDT Characteristic
Module Differential Current Watchdog Timer PIC18LFXX2 Watchdog Timer PIC18FXX2 Brown-out Reset(5) PIC18LFXX2 Brown-out Reset(5) PIC18FXX2 Low Voltage Detect(5) PIC18LFXX2 Low Voltage Detect(5) PIC18FXX2 ITMR1 Timer1 Oscillator PIC18LFXX2 Timer1 Oscillator PIC18FXX2 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- .75 2 10 7 10 25 29 29 33 36 36 36 29 29 33 33 33 33 5.2 5.2 6.5 6.5 6.5 6.5 1.5 8 25 15 25 40 35 45 50 40 50 65 35 45 50 40 50 65 30 40 50 40 50 65 A A A A A A A A A A A A A A A A A A A A A A A A VDD = 2.0V, +25C VDD = 2.0V, -40C to +85C VDD = 4.2V, -40C to +85C VDD = 4.2V, +25C VDD = 4.2V, -40C to +85C VDD = 4.2V, -40C to +125C VDD = 2.0V, +25C VDD = 2.0V, -40C to +85C VDD = 4.2V, -40C to +85C VDD = 4.2V, +25C VDD = 4.2V, -40C to +85C VDD = 4.2V, -40C to +125C VDD = 2.0V, +25C VDD = 2.0V, -40C to +85C VDD = 4.2V, -40C to +85C VDD = 4.2V, +25C VDD = 4.2V, -40C to +85C VDD = 4.2V, -40C to +125C VDD = 2.0V, +25C VDD = 2.0V, -40C to +85C VDD = 4.2V, -40C to +85C VDD = 4.2V, +25C VDD = 4.2V, -40C to +85C VDD = 4.2V, -40C to +125C
D022
D022A IBOR
D022A
D022B ILVD
D022B
D025
D025
Legend: Shading of rows is to assist in readability of the table. Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...). 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm. 5: The LVD and BOR modules share a large portion of circuitry. The IBOR and ILVD currents are not additive. Once one of these modules is enabled, the other may also be enabled without further penalty.
DS39564B-page 264
2002 Microchip Technology Inc.
PIC18FXX2
22.2 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Characteristic Input Low Voltage I/O ports: D030 D030A D031 D032 D032A D033 VIH D040 D040A D041 D042 D042A D043 IIL D060 D061 D063 IPU D070 IPURB with Schmitt Trigger buffer RC3 and RC4 MCLR, OSC1 (EC mode) OSC1 (in XT, HS and LP modes) and T1OSI OSC1 (RC mode)(1) Input Leakage I/O ports MCLR OSC1 Weak Pull-up Current PORTB weak pull-up current 50 450 A VDD = 5V, VPIN = VSS Current(2,3) .02 -- -- 1 1 1 A A A VSS VPIN VDD, Pin at hi-impedance Vss VPIN VDD Vss VPIN VDD with Schmitt Trigger buffer RC3 and RC4 MCLR OSC1 (in XT, HS and LP modes) and T1OSI OSC1 (in RC and EC mode)(1) Input High Voltage I/O ports: with TTL buffer 0.25 VDD + 0.8V 2.0 0.8 VDD 0.7 VDD 0.8 VDD 0.7 VDD 0.9 VDD VDD VDD VDD VDD VDD VDD VDD V V V V V V V VDD < 4.5V 4.5V VDD 5.5V with TTL buffer Vss -- Vss Vss VSS VSS VSS 0.15 VDD 0.8 0.2 VDD 0.3 VDD 0.2 VDD 0.3 VDD 0.2 VDD V V V V V V V VDD < 4.5V 4.5V VDD 5.5V Min Max Units Conditions
DC CHARACTERISTICS Param Symbol No. VIL
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PICmicro device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: Parameter is characterized but not tested.
2002 Microchip Technology Inc.
DS39564B-page 265
PIC18FXX2
22.2 DC Characteristics: PIC18FXX2 (Industrial, Extended) PIC18LFXX2 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Characteristic Output Low Voltage I/O ports -- -- OSC2/CLKO (RC mode) -- -- VOH D090 D090A D092 D092A D150 VOD Open Drain High Voltage Capacitive Loading Specs on Output Pins D100(4) COSC2 OSC2 pin
--
DC CHARACTERISTICS Param Symbol No. VOL D080 D080A D083 D083A Output High Voltage(3) I/O ports
Min
Max
Units
Conditions
0.6 0.6 0.6 0.6
V V V V
IOL = 8.5 mA, VDD = 4.5V, -40C to +85C IOL = 7.0 mA, VDD = 4.5V, -40C to +125C IOL = 1.6 mA, VDD = 4.5V, -40C to +85C IOL = 1.2 mA, VDD = 4.5V, -40C to +125C IOH = -3.0 mA, VDD = 4.5V, -40C to +85C IOH = -2.5 mA, VDD = 4.5V, -40C to +125C IOH = -1.3 mA, VDD = 4.5V, -40C to +85C IOH = -1.0 mA, VDD = 4.5V, -40C to +125C RA4 pin
VDD - 0.7 VDD - 0.7
-- -- -- -- 8.5
V V V V V
OSC2/CLKO (RC mode)
VDD - 0.7 VDD - 0.7 --
15
pF
In XT, HS and LP modes when external clock is used to drive OSC1 To meet the AC Timing Specifications In I2C mode
D101 D102
CIO CB
All I/O pins and OSC2 (in RC mode) SCL, SDA
-- --
50 400
pF pF
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PICmicro device be driven with an external clock while in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: Parameter is characterized but not tested.
DS39564B-page 266
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-3: LOW VOLTAGE DETECT CHARACTERISTICS
VDD (LVDIF can be cleared in software)
VLVD (LVDIF set by hardware)
37
LVDIF
TABLE 22-1:
LOW VOLTAGE DETECT CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended
Param Symbol No. D420 VLVD
Characteristic LVD Voltage on VDD LVV = 0001 transition high to LVV = 0010 low LVV = 0011 LVV = 0100 LVV = 0101 LVV = 0110 LVV = 0111 LVV = 1000 LVV = 1001 LVV = 1010 LVV = 1011 LVV = 1100 LVV = 1101 LVV = 1110
Min 1.98 2.18 2.37 2.48 2.67 2.77 2.98 3.27 3.47 3.57 3.76 3.96 4.16 4.45
Typ 2.06 2.27 2.47 2.58 2.78 2.89 3.1 3.41 3.61 3.72 3.92 4.13 4.33 4.64
Max 2.14 2.36 2.57 2.68 2.89 3.01 3.22 3.55 3.75 3.87 4.08 4.3 4.5 4.83
Units V V V V V V V V V V V V V V
Conditions T 25C T 25C T 25C
2002 Microchip Technology Inc.
DS39564B-page 267
PIC18FXX2
TABLE 22-2: MEMORY PROGRAMMING REQUIREMENTS
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Characteristic Internal Program Memory Programming Specifications D110 D113 VPP IDDP Voltage on MCLR/VPP pin Supply Current during Programming Data EEPROM Memory D120 D121 ED VDRW Cell Endurance VDD for Read/Write 100K VMIN
1M -- --
DC Characteristics Param No.
Sym
Min
Typ
Max
Units
Conditions
9.00 --
-- --
13.25 10
V mA
E/W -40C to +85C V Using EECON to read/write VMIN = Minimum operating voltage
5.5
D122 D123 D124
TDEW
Erase/Write Cycle Time
--
4 -- 10M
--
ms Year Provided no other specifications are violated E/W -40C to +85C
TRETD Characteristic Retention TREF Number of Total Erase/Write Cycles before Refresh(1) Program FLASH Memory Cell Endurance VDD for Read VDD for Block Erase VDD for Externally Timed Erase or Write VDD for Self-timed Write ICSP Block Erase Cycle Time ICSP Erase or Write Cycle Time (externally timed) Self-timed Write Cycle Time
40 1M
-- --
D130 D131 D132
EP VPR VIE
10K VMIN 4.5 4.5 VMIN
--
100K
-- -- -- --
--
E/W -40C to +85C V V V V ms ms ms Year Provided no other specifications are violated VMIN = Minimum operating voltage Using ICSP port Using ICSP port VMIN = Minimum operating voltage VDD 4.5V VDD 4.5V
5.5 5.5 5.5 5.5
-- -- --
D132A VIW D132B VPEW D133 TIE
4
--
D133A TIW D133A TIW D134
1
--
2 --
TRETD Characteristic Retention
40
--
Data in "Typ" column is at 5.0V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Refer to Section 6.8 for a more detailed discussion on data EEPROM endurance.
DS39564B-page 268
2002 Microchip Technology Inc.
PIC18FXX2
22.3
22.3.1
AC (Timing) Characteristics
TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase letters (pp) and their meanings: pp cc CCP1 ck CLKO cs CS di SDI do SDO dt Data in io I/O port mc MCLR Uppercase letters and their meanings: S F Fall H High I Invalid (Hi-impedance) L Low 2C only I AA output access BUF Bus free TCC:ST (I2C specifications only) CC HD Hold ST DAT DATA input hold STA START condition 3. TCC:ST 4. Ts T (I2C specifications only) (I2C specifications only) Time
osc rd rw sc ss t0 t1 wr
OSC1 RD RD or WR SCK SS T0CKI T1CKI WR
P R V Z High Low
Period Rise Valid Hi-impedance High Low
SU STO
Setup STOP condition
2002 Microchip Technology Inc.
DS39564B-page 269
PIC18FXX2
22.3.2 TIMING CONDITIONS
The temperature and voltages specified in Table 22-3 apply to all timing specifications unless otherwise noted. Figure 22-4 specifies the load conditions for the timing specifications.
TABLE 22-3:
TEMPERATURE AND VOLTAGE SPECIFICATIONS - AC
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial -40C TA +125C for extended Operating voltage VDD range as described in DC spec Section 22.1 and Section 22.2. LC parts operate for industrial temperatures only.
AC CHARACTERISTICS
FIGURE 22-4:
LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS
Load condition 1 VDD/2 CL VSS Pin VSS CL RL = 464 CL = 50 pF for all pins except OSC2/CLKO and including D and E outputs as ports Load condition 2
RL
Pin
DS39564B-page 270
2002 Microchip Technology Inc.
PIC18FXX2
22.3.3 TIMING DIAGRAMS AND SPECIFICATIONS EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)
Q4 Q1 Q2 Q3 Q4 Q1
FIGURE 22-5:
OSC1
1 2 3 3 4 4
CLKO
TABLE 22-4:
Param. No. 1A
EXTERNAL CLOCK TIMING REQUIREMENTS
Characteristic External CLKI Frequency(1) Oscillator Frequency(1) Min DC DC DC 0.1 4 4 4 5 Max 40 25 4 4 25 10 6.25 200 -- -- -- 10,000 250 250 250 -- -- -- -- -- -- 20 50 7.5 Units MHz MHz MHz MHz MHz MHz MHz kHz ns ns ns ns ns ns ns s ns ns ns s ns ns ns ns Conditions EC, ECIO, -40C to +85C EC, ECIO, +85C to +125C RC osc XT osc HS osc HS + PLL osc, -40C to +85C HS + PLL osc, +85C to +125C LP Osc mode EC, ECIO, -40C to +85C EC, ECIO, +85C to +125C RC osc XT osc HS osc HS + PLL osc, -40C to +85C HS + PLL osc, +85C to +125C LP osc TCY = 4/FOSC, -40C to +85C TCY = 4/FOSC, +85C to +125C XT osc LP osc HS osc XT osc LP osc HS osc
Symbol FOSC
1
TOSC
External CLKI Period Oscillator Period(1)
(1)
25 40 250 250 40 100 160 25
2 3
TCY TosL, TosH
Instruction Cycle
Time(1)
100 160 30 2.5 10 -- -- --
External Clock in (OSC1) High or Low Time
4
TosR, TosF
External Clock in (OSC1) Rise or Fall Time
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time-base period for all configurations except PLL. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at "min." values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the "max." cycle time limit is "DC" (no clock) for all devices.
2002 Microchip Technology Inc.
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PIC18FXX2
TABLE 22-5:
Param No. -- -- -- -- Sym
PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2 TO 5.5V)
Characteristic Min 4 16 -- -2 Typ -- -- -- -- Max 10 40 2 +2 Units Conditions
FOSC Oscillator Frequency Range FSYS On-chip VCO System Frequency trc CLK PLL Start-up Time (Lock Time) CLKO Stability (Jitter)
MHz HS mode only MHz HS mode only ms %
Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested.
FIGURE 22-6:
CLKO AND I/O TIMING
Q4 Q1 Q2 Q3
OSC1 10 CLKO 13 14 I/O Pin (input) 17 I/O Pin (output) Old Value 20, 21 Note: Refer to Figure 22-4 for load conditions. 15 New Value 19 12 18 16 11
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2002 Microchip Technology Inc.
PIC18FXX2
TABLE 22-6:
Param. Symbol No. 10 11 12 13 14 15 16 17 18 18A 19 20 20A 21 21A 22 23 24 TINP TRBP TRCP INT pin high or low time RB7:RB4 change INT high or low time RC7:RC4 change INT high or low time TioF Port output fall time TioR
CLKO AND I/O TIMING REQUIREMENTS
Characteristic Min -- -- -- -- -- 0.25 TCY + 25 0 -- 100 200 0 -- -- -- -- TCY TCY 20 Typ 75 75 35 35 -- -- -- 50 -- -- -- 10 -- 10 -- -- -- Max 200 200 100 100 0.5 TCY + 20 -- -- 150 -- -- -- 25 60 25 60 -- -- Units Conditions ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2V VDD = 2V (Note 1) (Note 1) (Note 1) (Note 1) (Note 1) (Note 1) (Note 1)
TosH2ckL OSC1 to CLKO TosH2ckH OSC1 to CLKO TckR TckF CLKO rise time CLKO fall time
TckL2ioV CLKO to Port out valid TioV2ckH Port in valid before CLKO TckH2ioI TosH2ioI Port in hold after CLKO OSC1 (Q2 cycle) to Port PIC18FXXX input invalid (I/O in hold time) PIC18LFXXX Port output rise time PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX TosH2ioV OSC1 (Q1 cycle) to Port out valid
TioV2osH Port input valid to OSC1 (I/O in setup time)
These parameters are asynchronous events not related to any internal clock edges. Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.
FIGURE 22-7:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING
VDD MCLR Internal POR 33 PWRT Time-out OSC Time-out Internal Reset Watchdog Timer Reset 34 I/O Pins Note: Refer to Figure 22-4 for load conditions. 32 30
31
34
2002 Microchip Technology Inc.
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PIC18FXX2
FIGURE 22-8: BROWN-OUT RESET TIMING
BVDD VDD 35 VBGAP = 1.2V Typical
VIRVST
Enable Internal Reference Voltage Internal Reference Voltage stable 36
TABLE 22-7:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER AND BROWN-OUT RESET REQUIREMENTS
Characteristic MCLR Pulse Width (low) Watchdog Timer Time-out Period (No Postscaler) Oscillation Start-up Timer Period Power up Timer Period I/O Hi-impedance from MCLR Low or Watchdog Timer Reset Brown-out Reset Pulse Width Time for Internal Reference Voltage to become stable Low Voltage Detect Pulse Width Min 2 7 1024 TOSC 28 -- 200 -- 200 Typ -- 18 -- 72 2 -- 20 -- Max -- 33 1024 TOSC 132 -- -- 500 -- Units s ms -- ms s s s s VDD VLVD (see D420) VDD BVDD (see D005) TOSC = OSC1 period Conditions
Param. Symbol No. 30 31 32 33 34 35 36 37 TmcL TWDT TOST TPWRT TIOZ TBOR TIVRST TLVD
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PIC18FXX2
FIGURE 22-9:
T0CKI
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
40
41
42 T1OSO/T1CKI
45
46
47 TMR0 or TMR1 Note: Refer to Figure 22-4 for load conditions.
48
TABLE 22-8:
Param Symbol No. 40 41 42 Tt0H Tt0L Tt0P
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Characteristic T0CKI High Pulse Width T0CKI Low Pulse Width T0CKI Period No Prescaler With Prescaler No Prescaler With Prescaler No Prescaler With Prescaler Min 0.5TCY + 20 10 0.5TCY + 20 10 TCY + 10 Greater of: 20 nS or TCY + 40 N 0.5TCY + 20 10 25 30 50 0.5TCY + 5 10 25 30 50 Greater of: 20 nS or TCY + 40 N 60 DC 2 TOSC Max -- -- -- -- -- -- Units ns ns ns ns ns ns N = prescale value (1, 2, 4,..., 256) Conditions
45
Tt1H
T1CKI High Time
Synchronous, no prescaler Synchronous, with prescaler Asynchronous PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX
-- -- -- -- -- -- -- -- -- -- --
ns ns ns ns ns ns ns ns ns ns ns N = prescale value (1, 2, 4, 8)
46
Tt1L
T1CKI Low Time
Synchronous, no prescaler Synchronous, with prescaler Asynchronous PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX
47
Tt1P
T1CKI input period
Synchronous
Asynchronous Ft1 48 T1CKI oscillator input frequency range Tcke2tmrI Delay from external T1CKI clock edge to timer increment
-- 50 7 TOSC
ns kHz --
2002 Microchip Technology Inc.
DS39564B-page 275
PIC18FXX2
FIGURE 22-10: CAPTURE/COMPARE/PWM TIMINGS (CCP1 AND CCP2)
CCPx (Capture Mode)
50 52
51
CCPx (Compare or PWM Mode) 53 Note: Refer to Figure 22-4 for load conditions. 54
TABLE 22-9:
Param. Symbol No. 50 TccL
CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1 AND CCP2)
Characteristic CCPx input low No Prescaler time With PIC18FXXX Prescaler PIC18LFXXX CCPx input high time No Prescaler With Prescaler PIC18FXXX PIC18LFXXX Min 0.5 TCY + 20 10 20 0.5 TCY + 20 10 20 3 TCY + 40 N PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX -- -- -- -- Max -- -- -- -- -- -- -- 25 60 25 60 Units ns ns ns ns ns ns ns ns ns ns ns VDD = 2V VDD = 2V N = prescale value (1,4 or 16) Conditions
51
TccH
52 53 54
TccP TccR TccF
CCPx input period CCPx output fall time CCPx output fall time
DS39564B-page 276
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-11:
RE2/CS
PARALLEL SLAVE PORT TIMING (PIC18F4X2)
RE0/RD
RE1/WR
65 RD7:RD0 62 63 Note: Refer to Figure 22-4 for load conditions.
64
TABLE 22-10: PARALLEL SLAVE PORT REQUIREMENTS (PIC18F4X2)
Param. No. 62 63 64 65 66 Symbol TdtV2wrH TwrH2dtI TrdL2dtV TrdH2dtI TibfINH Characteristic Data in valid before WR or CS (setup time) WR or CS to data-in invalid PIC18FXXX (hold time) PIC18LFXXX RD and CS to data-out valid RD or CS to data-out invalid Inhibit of the IBF flag bit being cleared from WR or CS Min 20 25 20 35 -- -- 10 -- Max -- -- -- -- 80 90 30 3 TCY Units ns ns ns ns ns ns ns VDD = 2V Extended Temp. Range Conditions
Extended Temp. Range
2002 Microchip Technology Inc.
DS39564B-page 277
PIC18FXX2
FIGURE 22-12:
SS 70 SCK (CKP = 0) 71 72
EXAMPLE SPI MASTER MODE TIMING (CKE = 0)
78
79
SCK (CKP = 1) 79 78
80 SDO MSb 75, 76 SDI MSb In 74 73 Note: Refer to Figure 22-4 for load conditions. bit6 - - - -1 bit6 - - - - - -1
LSb
LSb In
TABLE 22-11: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Param. No. 70 71 71A 72 72A 73 73A 74 75 76 78 79 80 TscL Symbol Characteristic Min TCY Continuous Single Byte Continuous Single Byte 1.25 TCY + 30 40 1.25 TCY + 30 40 100 1.5 TCY + 40 100 -- -- -- -- -- -- -- -- -- -- Max Units Conditions -- -- -- -- -- -- -- -- 25 60 25 60 25 60 25 60 50 150 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2V VDD = 2V VDD = 2V VDD = 2V VDD = 2V (Note 2) (Note 1) (Note 1)
TssL2scH, SS to SCK or SCK input TssL2scL TscH SCK input high time (Slave mode) SCK input low time (Slave mode)
TdiV2scH, Setup time of SDI data input to SCK edge TdiV2scL TB2B Last clock edge of Byte1 to the 1st clock edge of Byte2 TscH2diL, Hold time of SDI data input to SCK edge TscL2diL TdoR TdoF TscR TscF SDO data output rise time SDO data output fall time SCK output rise time (Master mode) PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX PIC18LFXXX TscH2doV, SDO data output valid after SCK TscL2doV edge PIC18FXXX PIC18LFXXX
SCK output fall time (Master mode) PIC18FXXX
Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used.
DS39564B-page 278
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-13:
SS 81 SCK (CKP = 0) 71 73 SCK (CKP = 1) 80 78 72 79
EXAMPLE SPI MASTER MODE TIMING (CKE = 1)
SDO
MSb 75, 76
bit6 - - - - - -1
LSb
SDI
MSb In 74
bit6 - - - -1
LSb In
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-12: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Param. No. 71 71A 72 72A 73 73A 74 75 76 78 79 80 81 TscL Symbol TscH Characteristic SCK input high time (Slave mode) SCK input low time (Slave mode) Continuous Single Byte Continuous Single Byte Min 1.25 TCY + 30 40 1.25 TCY + 30 40 100 1.5 TCY + 40 100 -- -- -- -- -- -- -- -- -- -- TCY Max Units Conditions -- -- -- -- -- -- -- 25 60 25 60 25 60 25 60 50 150 -- ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns VDD = 2V VDD = 2V VDD = 2V VDD = 2V VDD = 2V (Note 2) (Note 1) (Note 1)
TdiV2scH, Setup time of SDI data input to SCK edge TdiV2scL TB2B TscH2diL, TscL2diL TdoR TdoF TscR TscF Last clock edge of Byte1 to the 1st clock edge of Byte2 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX SCK output rise time (Master mode) PIC18FXXX PIC18LFXXX SCK output fall time (Master mode) PIC18FXXX PIC18LFXXX TscH2doV, SDO data output valid after SCK TscL2doV edge TdoV2scH, SDO data output setup to SCK edge TdoV2scL PIC18FXXX PIC18LFXXX
Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used.
2002 Microchip Technology Inc.
DS39564B-page 279
PIC18FXX2
FIGURE 22-14:
SS 70 SCK (CKP = 0) 71 72 83
EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)
78
79
SCK (CKP = 1) 79 78
80 SDO MSb 75, 76 SDI 73 Note: Refer to Figure 22-4 for load conditions. MSb In 74 bit6 - - - -1 bit6 - - - - - -1
LSb 77 LSb In
TABLE 22-13: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING (CKE = 0))
Param. No. 70 71 71A 72 72A 73 73A 74 75 76 TdiV2scH, TdiV2scL TB2B TscH2diL, TscL2diL TdoR TdoF TscL SCK input low time (Slave mode) Symbol TssL2scH, TssL2scL TscH Characteristic SS to SCK or SCK input SCK input high time (Slave mode) Continuous Single Byte Continuous Single Byte Setup time of SDI data input to SCK edge Last clock edge of Byte1 to the first clock edge of Byte2 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX 77 78 79 80 TssH2doZ TscR TscF SS to SDO output hi-impedance SCK output rise time (Master mode) SCK output fall time (Master mode) PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX TscH2doV, SDO data output valid after SCK edge PIC18FXXX TscL2doV PIC18LFXXX TscH2ssH, SS after SCK edge TscL2ssH Min TCY 1.25 TCY + 30 40 1.25 TCY + 30 40 100 1.5 TCY + 40 100 -- -- -- -- 10 -- -- -- -- -- -- 1.5 TCY + 40 Max -- -- -- -- -- -- -- -- 25 60 25 60 50 25 60 25 60 50 150 -- Units Conditions ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns (Note 2) (Note 1) (Note 1)
VDD = 2V VDD = 2V
VDD = 2V VDD = 2V VDD = 2V
83
Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used.
DS39564B-page 280
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-15:
SS
EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)
82
SCK (CKP = 0)
70 83 71 72
SCK (CKP = 1) 80 SDO MSb 75, 76 SDI MSb In 74 Note: Refer to Figure 22-4 for load conditions. bit6 - - - -1 LSb In bit6 - - - - - -1 LSb 77
TABLE 22-14: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param. No. 70 71 71A 72 72A 73A 74 75 76 TB2B TscH2diL, TscL2diL TdoR TdoF TscL Symbol Characteristic Min TCY Continuous Single Byte Continuous Single Byte 1.25 TCY + 30 40 1.25 TCY + 30 40 100 -- -- -- -- 10 PIC18FXXX PIC18LFXXX 79 80 TscF SCK output fall time (Master mode) PIC18FXXX PIC18LFXXX TscH2doV, SDO data output valid after SCK TscL2doV edge TssL2doV PIC18FXXX PIC18LFXXX PIC18LFXXX 83 TscH2ssH, SS after SCK edge TscL2ssH -- -- -- -- -- -- -- -- 1.5 TCY + 40 Max -- -- -- -- -- -- -- 25 60 25 60 50 25 60 25 60 50 150 50 150 -- Units Conditions ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns (Note 1) (Note 2) (Note 1)
TssL2scH, SS to SCK or SCK input TssL2scL TscH SCK input high time (Slave mode) SCK input low time (Slave mode)
Last clock edge of Byte1 to the first clock edge of Byte2 1.5 TCY + 40 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX
VDD = 2V VDD = 2V
77 78
TssH2doZ TscR
SS to SDO output hi-impedance SCK output rise time (Master mode)
VDD = 2V VDD = 2V VDD = 2V VDD = 2V
82
SDO data output valid after SS edge PIC18FXXX
Note 1: Requires the use of Parameter # 73A. 2: Only if Parameter # 71A and # 72A are used.
2002 Microchip Technology Inc.
DS39564B-page 281
PIC18FXX2
FIGURE 22-16: I2C BUS START/STOP BITS TIMING
SCL 90 SDA
91 92
93
START Condition
STOP Condition
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-15: I2C BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
Param. Symbol No. 90 91 92 93 TSU:STA THD:STA TSU:STO Setup time START condition Hold time STOP condition Setup time THD:STO STOP condition Hold time Characteristic START condition 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode Min 4700 600 4000 600 4700 600 4000 600 Max -- -- -- -- -- -- -- -- ns ns ns Units ns Conditions Only relevant for Repeated START condition After this period, the first clock pulse is generated
FIGURE 22-17:
I2C BUS DATA TIMING
103 100 101 102
SCL
90 91 106 107 92
SDA In
110 109 109
SDA Out Note: Refer to Figure 22-4 for load conditions.
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2002 Microchip Technology Inc.
PIC18FXX2
TABLE 22-16: I2C BUS DATA REQUIREMENTS (SLAVE MODE)
Param. No. Symbol Characteristic Clock high time 100 kHz mode 400 kHz mode SSP Module Min 4.0 0.6 1.5 TCY 4.7 1.3 1.5 TCY -- 20 + 0.1 CB -- 20 + 0.1 CB 4.7 0.6 4.0 0.6 0 0 250 100 4.7 0.6 -- -- 4.7 1.3 -- Max -- -- -- -- -- -- 1000 300 1000 300 -- -- -- -- -- 0.9 -- -- -- -- 3500 -- -- -- 400 ns ns ns ns
s s s s s s
Units
s s
Conditions PIC18FXXX must operate at a minimum of 1.5 MHz PIC18FXXX must operate at a minimum of 10 MHz PIC18FXXX must operate at a minimum of 1.5 MHz PIC18FXXX must operate at a minimum of 10 MHz
100
THIGH
101
TLOW
Clock low time
100 kHz mode 400 kHz mode SSP Module
102
TR
SDA and SCL rise time SDA and SCL fall time START condition setup time
100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode
CB is specified to be from 10 to 400 pF VDD 4.2V VDD 4.2V Only relevant for Repeated START condition After this period, the first clock pulse is generated
103 90 91 106 107 92 109 110
TF TSU:STA THD:STA THD:DAT TSU:DAT TSU:STO TAA TBUF
START condition hold 100 kHz mode time 400 kHz mode Data input hold time 100 kHz mode 400 kHz mode Data input setup time 100 kHz mode 400 kHz mode STOP condition setup time Output valid from clock Bus free time 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode
ns
s
ns ns
s s
(Note 2)
ns ns
s s
(Note 1) Time the bus must be free before a new transmission can start
D102
CB
Bus capacitive loading
pF
Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions. 2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but the requirement TSU:DAT 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line. TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification) before the SCL line is released.
2002 Microchip Technology Inc.
DS39564B-page 283
PIC18FXX2
FIGURE 22-18: MASTER SSP I2C BUS START/STOP BITS TIMING WAVEFORMS
SCL 90 SDA
91 92
93
START Condition Note: Refer to Figure 22-4 for load conditions.
STOP Condition
TABLE 22-17: MASTER SSP I2C BUS START/STOP BITS REQUIREMENTS
Param. Symbol No. 90 TSU:STA Characteristic START condition Setup time 91 THD:STA START condition Hold time 92 TSU:STO STOP condition Setup time 93 THD:STO STOP condition Hold time 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1)
2
Min 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1)
Max -- -- -- -- -- -- -- -- -- -- -- --
Units ns
Conditions Only relevant for Repeated START condition After this period, the first clock pulse is generated
ns
ns
ns
Note 1: Maximum pin capacitance = 10 pF for all I C pins.
FIGURE 22-19:
MASTER SSP I2C BUS DATA TIMING
103 100 101 102
SCL SDA In
90
91
106
107
92
109
109
110
SDA Out Note: Refer to Figure 22-4 for load conditions.
DS39564B-page 284
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 22-18: MASTER SSP I2C BUS DATA REQUIREMENTS
Param. Symbol No. 100 THIGH Characteristic Clock high time 100 kHz mode 400 kHz mode 1 MHz mode 101 TLOW Clock low time
(1)
Min 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) -- 20 + 0.1 CB -- -- 20 + 0.1 CB 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 0 0 250 100 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) -- -- -- 4.7 1.3 --
Max -- -- -- -- -- -- 1000 300 300 1000 300 -- -- -- -- -- -- -- 0.9 -- -- -- -- -- 3500 1000 -- -- -- 400
Units ms ms ms ms ms ms ns ns ns ns ns ms ms ms ms ms ms ns ms ns ns ms ms ms ns ns ns ms ms pF
Conditions
100 kHz mode 400 kHz mode 1 MHz mode
(1)
102
TR
SDA and SCL rise time
100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode
CB is specified to be from 10 to 400 pF VDD 4.2V VDD 4.2V Only relevant for Repeated START condition After this period, the first clock pulse is generated
103 90
TF TSU:STA
SDA and SCL fall time
START condition 100 kHz mode setup time 400 kHz mode 1 MHz mode(1)
91
THD:STA START condition 100 kHz mode hold time 400 kHz mode 1 MHz mode(1) THD:DAT Data input hold time TSU:DAT Data input setup time 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 1 MHz mode
(1)
106 107 92
(Note 2)
TSU:STO STOP condition setup time
109
TAA
Output valid from 100 kHz mode clock 400 kHz mode 1 MHz mode(1) Bus free time 100 kHz mode 400 kHz mode
110
TBUF
Time the bus must be free before a new transmission can start
D102
CB
Bus capacitive loading
Note 1: Maximum pin capacitance = 10 pF for all I2C pins. 2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line is released.
2002 Microchip Technology Inc.
DS39564B-page 285
PIC18FXX2
FIGURE 22-20: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
RC6/TX/CK pin RC7/RX/DT pin 120 Note:
121
121
122
Refer to Figure 22-4 for load conditions.
TABLE 22-19: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Param. No. 120 Symbol Characteristic Min Max Units Conditions
TckH2dtV SYNC XMIT (MASTER & SLAVE) Clock high to data out valid Tckr Tdtr Clock out rise time and fall time (Master mode) Data out rise time and fall time
PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX PIC18FXXX PIC18LFXXX
-- -- -- -- -- --
50 150 25 60 25 60
ns ns ns ns ns ns VDD = 2V VDD = 2V VDD = 2V
121 122
FIGURE 22-21:
RC6/TX/CK pin RC7/RX/DT pin
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
125
126 Note: Refer to Figure 22-4 for load conditions.
TABLE 22-20: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Param. Symbol No. 125 126 Characteristic Min Max Units Conditions
TdtV2ckl SYNC RCV (MASTER & SLAVE) Data hold before CK (DT hold time) TckL2dtl Data hold after CK (DT hold time) PIC18FXXX PIC18LFXXX
10 15 20
-- -- --
ns ns ns VDD = 2V
DS39564B-page 286
2002 Microchip Technology Inc.
PIC18FXX2
TABLE 22-21: A/D CONVERTER CHARACTERISTICS: PIC18FXX2 (INDUSTRIAL, EXTENDED) PIC18LFXX2 (INDUSTRIAL)
Param Symbol No. A01 A03 A04 A05 A06 A10 A20 A20A A21 A22 A25 A30 A50 NR EIL EDL EG EOFF -- VREF VREFH VREFL VAIN ZAIN IREF Characteristic Resolution Integral linearity error Differential linearity error Gain error Offset error Monotonicity Reference Voltage (VREFH - VREFL) Reference voltage High Reference voltage Low Analog input voltage Recommended impedance of analog voltage source VREF input current (Note 1) 1.8V 3V AVSS AVSS - 0.3V AVSS - 0.3V -- -- -- Min -- -- -- -- -- Typ -- -- -- -- -- guaranteed(2) -- -- -- -- -- -- -- -- -- -- AVDD + 0.3V VREFH AVDD + 0.3V 2.5 5 150 Max 10 <1 <1 <1 <1.5 Units bit LSb VREF = VDD = 5.0V LSb VREF = VDD = 5.0V LSb VREF = VDD = 5.0V LSb VREF = VDD = 5.0V -- V V V V V k A A VDD 2.5V (Note 3) (Note 4) During VAIN acquisition During A/D conversion cycle VSS VAIN VREF VDD < 3.0V VDD 3.0V Conditions
Note 1: 2: 3: 4:
Vss VAIN VREF The A/D conversion result never decreases with an increase in the Input Voltage, and has no missing codes. For VDD < 2.5V, VAIN should be limited to < .5 VDD. Maximum allowed impedance for analog voltage source is 10 k. This requires higher acquisition times.
FIGURE 22-22:
A/D CONVERSION TIMING
BSF ADCON0, GO (Note 2) Q4 130 A/D CLK 132 131
A/D DATA
9
8
7
...
...
2
1
0
ADRES
OLD_DATA
NEW_DATA
ADIF GO SAMPLING STOPPED DONE
TCY
SAMPLE
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. 2: This is a minimal RC delay (typically 100 nS), which also disconnects the holding capacitor from the analog input.
2002 Microchip Technology Inc.
DS39564B-page 287
PIC18FXX2
TABLE 22-22: A/D CONVERSION REQUIREMENTS
Param Symbol No. 130 131 132 135 TAD TCNV TACQ TSWC Characteristic A/D clock period PIC18FXXX PIC18FXXX Conversion time (not including acquisition time) (Note 1) Acquisition time (Note 2) Switching Time from convert sample Min 1.6 2.0 11 5 10 -- Max 20(4) 6.0 12 -- -- (Note 3) Units s s TAD s s
VREF = VDD = 5.0V VREF = VDD = 2.5V
Conditions TOSC based A/D RC mode
Note 1: ADRES register may be read on the following TCY cycle. 2: The time for the holding capacitor to acquire the "New" input voltage, when the new input value has not changed by more than 1 LSB from the last sampled voltage. The source impedance (RS) on the input channels is 50. See Section 17.0 for more information on acquisition time consideration. 3: On the next Q4 cycle of the device clock. 4: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
DS39564B-page 288
2002 Microchip Technology Inc.
PIC18FXX2
23.0
Note:
DC AND AC CHARACTERISTICS GRAPHS AND TABLES
The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore, outside the warranted range.
"Typical" represents the mean of the distribution at 25C. "Maximum" or "minimum" represents (mean + 3) or (mean - 3) respectively, where is a standard deviation, over the whole temperature range.
FIGURE 23-1:
12
TYPICAL IDD vs. FOSC OVER VDD (HS MODE)
10
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
5.0V
8
4.5V
IDD (mA)
4.0V 6 3.5V
4
3.0V
2
2.5V
2.0V 0 4 6 8 10 12 14 16 18 20 22 24 26 FOSC (M H z)
FIGURE 23-2:
12
MAXIMUM IDD vs. FOSC OVER VDD (HS MODE)
5.5V
10
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.0V
4.5V 8 4.0V IDD (mA)
3.5V 6
4
3.0V
2
2.5V
2.0V 0 4 6 8 10 12 14 16 18 20 22 24 26 FOSC (M H z)
2002 Microchip Technology Inc.
DS39564B-page 289
PIC18FXX2
FIGURE 23-3:
20
TYPICAL IDD vs. FOSC OVER VDD (HS/PLL MODE)
18
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
16
14
5.0V 4.5V
12 IDD (mA)
10
4.2V
8
6
4
2
0 4 5 6 7 FOSC (MHz) 8 9 10
FIGURE 23-4:
20
MAXIMUM IDD vs. FOSC OVER VDD (HS/PLL MODE)
18
16
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
5.0V 4.5V
14
12 IDD (mA) 4.2V 10
8
6
4
2
0 4 5 6 7 FOSC (MHz) 8 9 10
DS39564B-page 290
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-5:
2,000
TYPICAL IDD vs. FOSC OVER VDD (XT MODE)
1,800
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
1,600
5.0V
1,400
4.5V
1,200
4.0V 3.5V 3.0V 2.5V
IDD (A) IDD (uA)
1,000
800
600
2.0V
400
200
0 0.0 0.5 1.0 1.5 2.0 FOSC (MHz) 2.5 3.0 3.5 4.0
FIGURE 23-6:
2,000
MAXIMUM IDD vs. FOSC OVER VDD (XT MODE)
5.5V 1,800
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.0V 4.5V
1,600
1,400 4.0V 1,200 IDD (P A) 3.5V 1,000 3.0V 800 2.5V 600 2.0V
400
200
0 0.0 0.5 1.0 1.5 2.0 FOSC (MHz) 2.5 3.0 3.5 4.0
2002 Microchip Technology Inc.
DS39564B-page 291
PIC18FXX2
FIGURE 23-7:
100
TYPICAL IDD vs. FOSC OVER VDD (LP MODE)
90
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
80 5.5V 70 5.0V 60 IDD (uA) 4.5V 50 4.0V 40 3.5V 3.0V 30 2.5V 20 2.0V 10
0 20 30 40 50 60 FOSC (kHz) 70 80 90 100
FIGURE 23-8:
140
MAXIMUM IDD vs. FOSC OVER VDD (LP MODE)
120
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
100
5.0V
4.5V 80 IDD (uA) 4.0V 3.5V 60 3.0V 40 2.5V 2.0V
20
0 20 30 40 50 60 FOSC (kHz) 70 80 90 100
DS39564B-page 292
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-9:
16
TYPICAL IDD vs. FOSC OVER VDD (EC MODE)
14
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
5.0V 12 4.5V 10 IDD (mA) 4.0V 8 4.2V
6
3.5V
4 3.0V 2
2.5V 2.0V 4 8 12 16 20 FOSC (MHz) 24 28 32 36 40
0
FIGURE 23-10:
16
MAXIMUM IDD vs. FOSC OVER VDD (EC MODE)
14
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
5.5V
5.0V 12 4.5V 10 IDD (mA) 4.2V
4.0V
8 3.5V 6
4
3.0V
2 2.0V 0 4 8 12
2.5V
16
20 FOSC (MHz)
24
28
32
36
40
2002 Microchip Technology Inc.
DS39564B-page 293
PIC18FXX2
FIGURE 23-11: TYPICAL AND MAXIMUM IDD vs. VDD (TIMER1 AS MAIN OSCILLATOR, 32.768 kHz, C1 AND C2 = 47 pF)
180
160
140
Typical: statistical mean @ 25C Maximum: mean + 3 (-10C to 70C) Minimum: mean - 3 (-10C to 70C)
120
IDD (A) IPD (uA)
100
80
Max (+70C) Max (70C)
60
Typ (+25C) Typ (25C)
40
20
0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-12:
AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 20 pF, +25C)
4,500 Operation above 4 MHz is not recommended. 4,000 3.3k
3,500
3,000 5.1k Freq (kHz) 2,500
2,000
1,500 10k 1,000
500 100k 0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
DS39564B-page 294
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-13: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 100 pF, +25C)
2,000
1,800
1,600 3.3k 1,400
1,200 Freq (kHz) 5.1k 1,000
800
600
10k
400
200 100k 0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-14:
AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 300 pF, +25C)
800
700
600
3.3k
500 Freq (MHz) 5.1k 400
300 10k 200
100 100k 0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
2002 Microchip Technology Inc.
DS39564B-page 295
PIC18FXX2
FIGURE 23-15:
100
IPD vs. VDD, -40C TO +125C (SLEEP MODE, ALL PERIPHERALS DISABLED)
Max (-40C to +125C) 10 Max (+85C) IPD (uA)
1
Typ (+25C) 0.1
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
0.01 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-16:
90
IBOR vs. VDD OVER TEMPERATURE (BOR ENABLED, VBOR = 2.00 - 2.16V)
80
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
70
60
Device Device Held in Held in RESET Reset
Max (+125C) Max (125C)
IDD (P A)
50
Max (+85C) Max (85C)
40
Typ (+25C) Typ (25C)
30
20
Device Device in in SLEEP Sleep
10
0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
DS39564B-page 296
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-17: TYPICAL AND MAXIMUM ITMR1 vs. VDD OVER TEMPERATURE (-10C TO +70C, TIMER1 WITH OSCILLATOR, XTAL = 32 kHz, C1 AND C2 = 47 pF)
14
12
Typical: statistical mean @ 25C Maximum: mean + 3 (-10C to 70C) Minimum: mean - 3 (-10C to 70C)
10
Max (70C) Max (+70C)
8
IPD (uA) (A)
Typ (+25C) Typ (25C)
6
4
2
0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-18:
70
TYPICAL AND MAXIMUM IWDT vs. VDD OVER TEMPERATURE (WDT ENABLED)
60
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
50
40 IPD (P A)
Max (+125C) Max (125C)
30
Max (+85C) Max (85C)
20
10
Typ (+25C) Typ (25C)
0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
2002 Microchip Technology Inc.
DS39564B-page 297
PIC18FXX2
FIGURE 23-19:
50
TYPICAL, MINIMUM AND MAXIMUM WDT PERIOD vs. VDD (-40C TO +125C)
45
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
40
Max Max (+125C) (125C)
35
Max MAX (+85C) (85C)
WDT Period (ms) 30
25
Typ (+25C) (25C)
20
15
Min Min (-40C) (-40C)
10
5
0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-20:
90
ILVD vs. VDD OVER TEMPERATURE (LVD ENABLED, VLVD = 4.5 - 4.78V)
80
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
Max (+125C) Max (125C)
70
60
Max (+125C) Max (125C)
IDD (P A) 50
40
Typ (+25C) Typ (25C)
Typ (+25C) Typ (25C)
30 LVDIF can be cleared by firmware LVDIF state is unknown 10 LVDIF is set by hardware 0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
20
DS39564B-page 298
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-21:
5.5 5.0 4.5
TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 5V, -40C TO +125C)
Max Max
4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 5 10 IOH (-mA) 15 20 25
Typ (+25C) Typ (25C)
VOH (V)
Min Min
FIGURE 23-22:
3.0
TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 3V, -40C TO +125C)
2.5
2.0
Max Max
VOH (V)
1.5
Typ (+25C) Typ (25C)
1.0
Min Min
0.5
0.0 0 5 10 IOH (-mA) 15 20 25
2002 Microchip Technology Inc.
DS39564B-page 299
PIC18FXX2
FIGURE 23-23:
1.8
TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 5V, -40C TO +125C)
1.6
1.4
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
1.2
VOL (V)
1.0
Max Max
0.8
0.6
0.4
Typ (+25C) Typ (25C)
0.2
0.0 0 5 10 IOL (-mA) 15 20 25
FIGURE 23-24:
2.5
TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 3V, -40C TO +125C)
2.0
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
1.5 VOL (V) 1.0
Max Max
Typ (+25C) Typ (25C)
0.5
0.0 0 5 10 IOL (-mA) 15 20 25
DS39564B-page 300
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-25:
4.0
MINIMUM AND MAXIMUM VIN vs. VDD (ST INPUT, -40C TO +125C)
3.5
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
VIH Max
3.0
2.5 VIH Min VIN (V) 2.0 VIL Max 1.5
1.0 VIL Min 0.5
0.0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-26:
1.6
MINIMUM AND MAXIMUM VIN vs. VDD (TTL INPUT, -40C TO +125C)
1.4
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
VTH (Max)
1.2 VTH (Min) 1.0 VIN (V)
0.8
0.6
0.4
0.2
0.0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
2002 Microchip Technology Inc.
DS39564B-page 301
PIC18FXX2
FIGURE 23-27:
3.5 VIH Max 3.0
MINIMUM AND MAXIMUM VIN vs. VDD (I2C INPUT, -40C TO +125C)
Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C)
2.5
2.0 VIN (V)
VILMax VIH Min
1.5
1.0 VIL Min 0.5
0.0 2.0 2.5 3.0 3.5 VDD (V) 4.0 4.5 5.0 5.5
FIGURE 23-28:
4
A/D NON-LINEARITY vs. VREFH (VDD = VREFH, -40C TO +125C)
3.5
-40C -40C
Differential or Integral Nonlinearity (LSB) 3
+25C 25C
2.5
+85C 85C
2
1.5
1
0.5
+125C 125C
0 2 2.5 3 3.5 4 4.5 5 5.5 VDD and VREFH (V)
DS39564B-page 302
2002 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-29:
3
A/D NON-LINEARITY vs. VREFH (VDD = 5V, -40C TO +125C)
2.5 Differential or Integral Nonlinearilty (LSB)
2
1.5
Max (-40Cto 125C) Max (-40C to +125C)
1
Typ (+25C) Typ (25C)
0.5
0 2 2.5 3 3.5 VREFH (V) 4 4.5 5 5.5
2002 Microchip Technology Inc.
DS39564B-page 303
PIC18FXX2
NOTES:
DS39564B-page 304
2002 Microchip Technology Inc.
PIC18FXX2
24.0
24.1
PACKAGING INFORMATION
Package Marking Information
28-Lead PDIP (Skinny DIP)
XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN
Example
PIC18F242-I/SP 0217017
28-Lead SOIC
XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN
Example
PIC18F242-E/SO
0210017
Legend:
XX...X Y YY WW NNN
Customer specific information* Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code
Note:
In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line thus limiting the number of available characters for customer specific information.
*
Standard PICmicro device marking consists of Microchip part number, year code, week code, and traceability code. For PICmicro device marking beyond this, certain price adders apply. Please check with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP price.
2002 Microchip Technology Inc.
DS39564B-page 305
PIC18FXX2
Package Marking Information (Cont'd)
40-Lead PDIP
XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX YYWWNNN
Example
PIC18F442-I/P 0212017
44-Lead TQFP
Example
XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN
PIC18F452 -E/PT 0220017
44-Lead PLCC
Example
XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN
PIC18F442 -I/L 0220017
DS39564B-page 306
2002 Microchip Technology Inc.
PIC18FXX2
24.2 Package Details
The following sections give the technical details of the packages.
28-Lead Skinny Plastic Dual In-line (SP) - 300 mil (PDIP)
E1
D
2 n 1
E
A2 A L A1 B1 B p
c
eB
Units Number of Pins Pitch Top to Seating Plane Molded Package Thickness Base to Seating Plane Shoulder to Shoulder Width Molded Package Width Overall Length Tip to Seating Plane Lead Thickness Upper Lead Width Lower Lead Width Overall Row Spacing Mold Draft Angle Top Mold Draft Angle Bottom Dimension Limits n p A A2 A1 E E1 D L c B1 B eB
INCHES* MIN NOM 28 .100 .140 .125 .015 .300 .275 1.345 .125 .008 .040 .016 .320 5 5 .310 .285 1.365 .130 .012 .053 .019 .350 10 10 .325 .295 1.385 .135 .015 .065 .022 .430 15 15 .150 .130 .160 .135 MAX MIN
MILLIMETERS NOM 28 2.54 3.56 3.18 0.38 7.62 6.99 34.16 3.18 0.20 1.02 0.41 8.13 5 5 7.87 7.24 34.67 3.30 0.29 1.33 0.48 8.89 10 10 8.26 7.49 35.18 3.43 0.38 1.65 0.56 10.92 15 15 3.81 3.30 4.06 3.43 MAX
* Controlling Parameter Significant Characteristic Notes: Dimension D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-095
Drawing No. C04-070
2002 Microchip Technology Inc.
DS39564B-page 307
PIC18FXX2
28-Lead Plastic Small Outline (SO) - Wide, 300 mil (SOIC)
E E1 p
D
B n h 45 c A

2 1
A2
L Units Dimension Limits n p A A2 A1 E E1 D h L c B
A1 INCHES* NOM 28 .050 .099 .091 .008 .407 .295 .704 .020 .033 4 .011 .017 12 12 MILLIMETERS NOM 28 1.27 2.36 2.50 2.24 2.31 0.10 0.20 10.01 10.34 7.32 7.49 17.65 17.87 0.25 0.50 0.41 0.84 0 4 0.23 0.28 0.36 0.42 0 12 0 12
MIN
MAX
MIN
MAX
Number of Pins Pitch Overall Height Molded Package Thickness Standoff Overall Width Molded Package Width Overall Length Chamfer Distance Foot Length Foot Angle Top Lead Thickness Lead Width Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic
.093 .088 .004 .394 .288 .695 .010 .016 0 .009 .014 0 0
.104 .094 .012 .420 .299 .712 .029 .050 8 .013 .020 15 15
2.64 2.39 0.30 10.67 7.59 18.08 0.74 1.27 8 0.33 0.51 15 15
Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-013 Drawing No. C04-052
DS39564B-page 308
2002 Microchip Technology Inc.
PIC18FXX2
40-Lead Plastic Dual In-line (P) - 600 mil (PDIP)
E1
D
n E
2 1
A c
A2 L
A1 eB Units Dimension Limits n p INCHES* NOM 40 .100 .175 .150
B1 B p MILLIMETERS NOM 40 2.54 4.06 4.45 3.56 3.81 0.38 15.11 15.24 13.46 13.84 51.94 52.26 3.05 3.30 0.20 0.29 0.76 1.27 0.36 0.46 15.75 16.51 5 10 5 10
MIN
MAX
MIN
MAX
Number of Pins Pitch Top to Seating Plane A .160 .190 Molded Package Thickness A2 .140 .160 Base to Seating Plane A1 .015 Shoulder to Shoulder Width E .595 .600 .625 Molded Package Width E1 .530 .545 .560 Overall Length D 2.045 2.058 2.065 Tip to Seating Plane L .120 .130 .135 c Lead Thickness .008 .012 .015 Upper Lead Width .030 .050 .070 B1 Lower Lead Width B .014 .018 .022 eB Overall Row Spacing .620 .650 .680 5 10 15 Mold Draft Angle Top Mold Draft Angle Bottom 5 10 15 * Controlling Parameter Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-011 Drawing No. C04-016
4.83 4.06 15.88 14.22 52.45 3.43 0.38 1.78 0.56 17.27 15 15
2002 Microchip Technology Inc.
DS39564B-page 309
PIC18FXX2
44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)
E E1 #leads=n1 p
D1
D
B n
2 1
CH x 45 A
c
L
A1 (F)
A2
Number of Pins Pitch Pins per Side Overall Height Molded Package Thickness Standoff Foot Length Footprint (Reference) Foot Angle Overall Width Overall Length Molded Package Width Molded Package Length Lead Thickness Lead Width Pin 1 Corner Chamfer Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic
Units Dimension Limits n p n1 A A2 A1 L (F) E D E1 D1 c B CH
MIN
.039 .037 .002 .018 0 .463 .463 .390 .390 .004 .012 .025 5 5
INCHES NOM 44 .031 11 .043 .039 .004 .024 .039 3.5 .472 .472 .394 .394 .006 .015 .035 10 10
MAX
MIN
.047 .041 .006 .030 7 .482 .482 .398 .398 .008 .017 .045 15 15
MILLIMETERS* NOM 44 0.80 11 1.00 1.10 0.95 1.00 0.05 0.10 0.45 0.60 1.00 0 3.5 11.75 12.00 11.75 12.00 9.90 10.00 9.90 10.00 0.09 0.15 0.30 0.38 0.64 0.89 5 10 5 10
MAX
1.20 1.05 0.15 0.75 7 12.25 12.25 10.10 10.10 0.20 0.44 1.14 15 15
Notes: Dimensions D1 and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-026 Drawing No. C04-076
DS39564B-page 310
2002 Microchip Technology Inc.
PIC18FXX2
44-Lead Plastic Leaded Chip Carrier (L) - Square (PLCC)
E E1 #leads=n1
D1 D
n12 CH2 x 45 CH1 x 45 A3 A2
35
A B1 B p D2
c
A1
E2 Units Dimension Limits n p INCHES* MIN NOM 44 .050 11 .165 .173 .145 .153 .020 .028 .024 .029 .040 .045 .000 .005 .685 .690 .685 .690 .650 .653 .650 .653 .590 .620 .590 .620 .008 .011 .026 .029 .013 .020 0 5 0 5
MAX
MIN
Number of Pins Pitch Pins per Side n1 Overall Height A .180 Molded Package Thickness .160 A2 Standoff A1 .035 A3 Side 1 Chamfer Height .034 Corner Chamfer 1 CH1 .050 Corner Chamfer (others) CH2 .010 Overall Width E .695 Overall Length D .695 Molded Package Width E1 .656 Molded Package Length D1 .656 Footprint Width E2 .630 Footprint Length .630 D2 c Lead Thickness .013 Upper Lead Width B1 .032 B .021 Lower Lead Width 10 Mold Draft Angle Top Mold Draft Angle Bottom 10 * Controlling Parameter Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-047 Drawing No. C04-048
MILLIMETERS NOM 44 1.27 11 4.19 4.39 3.68 3.87 0.51 0.71 0.61 0.74 1.02 1.14 0.00 0.13 17.40 17.53 17.40 17.53 16.51 16.59 16.51 16.59 14.99 15.75 14.99 15.75 0.20 0.27 0.66 0.74 0.33 0.51 0 5 0 5
MAX
4.57 4.06 0.89 0.86 1.27 0.25 17.65 17.65 16.66 16.66 16.00 16.00 0.33 0.81 0.53 10 10
2002 Microchip Technology Inc.
DS39564B-page 311
PIC18FXX2
NOTES:
DS39564B-page 312
2002 Microchip Technology Inc.
PIC18FXX2
APPENDIX A: REVISION HISTORY APPENDIX B:
Revision A (June 2001)
Original data sheet for the PIC18FXX2 family.
DEVICE DIFFERENCES
The differences between the devices listed in this data sheet are shown in Table B-1.
Revision B (August 2002)
This revision includes the DC and AC Characteristics Graphs and Tables. The Electrical Specifications in Section 22.0 have been updated and there have been minor corrections to the data sheet text.
TABLE B-1:
DEVICE DIFFERENCES
Feature PIC18F242 16 768 5 No 28-pin DIP 28-pin SOIC PIC18F252 32 1536 5 No 28-pin DIP 28-pin SOIC PIC18F442 16 768 8 Yes 40-pin DIP 44-pin PLCC 44-pin TQFP PIC18F452 32 1536 8 Yes 40-pin DIP 44-pin PLCC 44-pin TQFP
Program Memory (Kbytes) Data Memory (Bytes) A/D Channels Parallel Slave Port (PSP) Package Types
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APPENDIX C: CONVERSION CONSIDERATIONS APPENDIX D: MIGRATION FROM BASELINE TO ENHANCED DEVICES
This appendix discusses the considerations for converting from previous versions of a device to the ones listed in this data sheet. Typically, these changes are due to the differences in the process technology used. An example of this type of conversion is from a PIC16C74A to a PIC16C74B. Not Applicable
This section discusses how to migrate from a Baseline device (i.e., PIC16C5X) to an Enhanced MCU device (i.e., PIC18FXXX). The following are the list of modifications over the PIC16C5X microcontroller family: Not Currently Available
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APPENDIX E: MIGRATION FROM MID-RANGE TO ENHANCED DEVICES APPENDIX F: MIGRATION FROM HIGH-END TO ENHANCED DEVICES
A detailed discussion of the differences between the mid-range MCU devices (i.e., PIC16CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN716, "Migrating Designs from PIC16C74A/74B to PIC18F442". The changes discussed, while device specific, are generally applicable to all mid-range to enhanced device migrations. This Application Note is available as Literature Number DS00716.
A detailed discussion of the migration pathway and differences between the high-end MCU devices (i.e., PIC17CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN726, "PIC17CXXX to PIC18FXXX Migration". This Application Note is available as Literature Number DS00726.
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NOTES:
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INDEX
A
A/D ................................................................................... 181 A/D Converter Flag (ADIF Bit) ................................. 183 A/D Converter Interrupt, Configuring ....................... 184 Acquisition Requirements ........................................ 184 ADCON0 Register .................................................... 181 ADCON1 Register .................................................... 181 ADRESH Register .................................................... 181 ADRESH/ADRESL Registers .................................. 183 ADRESL Register .................................................... 181 Analog Port Pins ................................................ 99, 100 Analog Port Pins, Configuring .................................. 186 Associated Registers ............................................... 188 Configuring the Module ............................................ 184 Conversion Clock (TAD) ........................................... 186 Conversion Status (GO/DONE Bit) .......................... 183 Conversions ............................................................. 187 Converter Characteristics ........................................ 287 Equations Acquisition Time ............................................... 185 Minimum Charging Time .................................. 185 Examples Calculating the Minimum Required Acquisition Time ...................................... 185 Result Registers ....................................................... 187 Special Event Trigger (CCP) ............................ 120, 188 TAD vs. Device Operating Frequencies .................... 186 Use of the CCP2 Trigger .......................................... 188 Absolute Maximum Ratings ............................................. 259 AC (Timing) Characteristics ............................................. 269 Load Conditions for Device Timing Specifications ................................................... 270 Parameter Symbology ............................................. 269 Temperature and Voltage Specifications - AC ......... 270 Timing Conditions .................................................... 270 ACKSTAT Status Flag ..................................................... 155 ADCON0 Register ............................................................ 181 GO/DONE Bit ........................................................... 183 ADCON1 Register ............................................................ 181 ADDLW ............................................................................ 217 ADDWF ............................................................................ 217 ADDWFC ......................................................................... 218 ADRESH Register ............................................................ 181 ADRESH/ADRESL Registers ........................................... 183 ADRESL Register ............................................................ 181 Analog-to-Digital Converter. See A/D ANDLW ............................................................................ 218 ANDWF ............................................................................ 219 Assembler MPASM Assembler .................................................. 253 Block Diagrams A/D Converter .......................................................... 183 Analog Input Model .................................................. 184 Baud Rate Generator .............................................. 151 Capture Mode Operation ......................................... 119 Compare Mode Operation ....................................... 120 Low Voltage Detect External Reference Source ............................. 190 Internal Reference Source ............................... 190 MSSP I2C Mode ......................................................... 134 MSSP (SPI Mode) ................................................... 125 On-Chip Reset Circuit ................................................ 25 Parallel Slave Port (PORTD and PORTE) ............... 100 PIC18F2X2 .................................................................. 8 PIC18F4X2 .................................................................. 9 PLL ............................................................................ 19 PORTC (Peripheral Output Override) ........................ 93 PORTD (I/O Mode) .................................................... 95 PORTE (I/O Mode) .................................................... 97 PWM Operation (Simplified) .................................... 122 RA3:RA0 and RA5 Port Pins ..................................... 87 RA4/T0CKI Pin .......................................................... 88 RA6 Pin ..................................................................... 88 RB2:RB0 Port Pins .................................................... 91 RB3 Pin ..................................................................... 91 RB7:RB4 Port Pins .................................................... 90 Table Read Operation ............................................... 55 Table Write Operation ................................................ 56 Table Writes to FLASH Program Memory ................. 61 Timer0 in 16-bit Mode .............................................. 104 Timer0 in 8-bit Mode ................................................ 104 Timer1 ..................................................................... 108 Timer1 (16-bit R/W Mode) ....................................... 108 Timer2 ..................................................................... 112 Timer3 ..................................................................... 114 Timer3 (16-bit R/W Mode) ....................................... 114 USART Asynchronous Receive .................................... 174 Asynchronous Transmit ................................... 172 Watchdog Timer ...................................................... 204 BN .................................................................................... 220 BNC ................................................................................. 221 BNN ................................................................................. 221 BNOV ............................................................................... 222 BNZ .................................................................................. 222 BOR. See Brown-out Reset BOV ................................................................................. 225 BRA ................................................................................. 223 BRG. See Baud Rate Generator Brown-out Reset (BOR) ..................................................... 26 BSF .................................................................................. 223 BTFSC ............................................................................. 224 BTFSS ............................................................................. 224 BTG ................................................................................. 225 Bus Collision During a STOP Condition .......................... 163 BZ .................................................................................... 226
B
Baud Rate Generator ....................................................... 151 BC .................................................................................... 219 BCF .................................................................................. 220 BF Status Flag ................................................................. 155
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C
CALL ................................................................................ 226 Capture (CCP Module) ..................................................... 119 Associated Registers ............................................... 121 CCP Pin Configuration ............................................. 119 CCPR1H:CCPR1L Registers ................................... 119 Software Interrupt ..................................................... 119 Timer1/Timer3 Mode Selection ................................ 119 Capture/Compare/PWM (CCP) ........................................ 117 Capture Mode. See Capture CCP1 ........................................................................ 118 CCPR1H Register ............................................ 118 CCPR1L Register ............................................ 118 CCP2 ........................................................................ 118 CCPR2H Register ............................................ 118 CCPR2L Register ............................................ 118 Compare Mode. See Compare Interaction of Two CCP Modules ............................. 118 PWM Mode. See PWM Timer Resources ...................................................... 118 Clocking Scheme/Instruction Cycle .................................... 39 CLRF ................................................................................ 227 CLRWDT .......................................................................... 227 Code Examples 16 x 16 Signed Multiply Routine ................................. 72 16 x 16 Unsigned Multiply Routine ............................. 72 8 x 8 Signed Multiply Routine ..................................... 71 8 x 8 Unsigned Multiply Routine ................................. 71 Changing Between Capture Prescalers ................... 119 Data EEPROM Read ................................................. 67 Data EEPROM Refresh Routine ................................ 68 Data EEPROM Write .................................................. 67 Erasing a FLASH Program Memory Row .................. 60 Fast Register Stack .................................................... 39 How to Clear RAM (Bank1) Using Indirect Addressing ............................................ 50 Initializing PORTA ...................................................... 87 Initializing PORTB ...................................................... 90 Initializing PORTC ...................................................... 93 Initializing PORTD ...................................................... 95 Initializing PORTE ...................................................... 97 Loading the SSPBUF (SSPSR) Register ................. 128 Reading a FLASH Program Memory Word ................ 59 Saving STATUS, WREG and BSR Registers in RAM ............................................... 85 Writing to FLASH Program Memory ..................... 62-63 Code Protection ............................................................... 195 COMF ............................................................................... 228 Compare (CCP Module) ................................................... 120 Associated Registers ............................................... 121 CCP Pin Configuration ............................................. 120 CCPR1 Register ....................................................... 120 Software Interrupt ..................................................... 120 Special Event Trigger ........................109, 115, 120, 188 Timer1/Timer3 Mode Selection ................................ 120 Configuration Bits ............................................................. 195 Context Saving During Interrupts ....................................... 85 Conversion Considerations .............................................. 314 CPFSEQ .......................................................................... 228 CPFSGT ........................................................................... 229 CPFSLT ........................................................................... 229
D
Data EEPROM Memory Associated Registers ................................................. 69 EEADR Register ........................................................ 65 EECON1 Register ...................................................... 65 EECON2 Register ...................................................... 65 Operation During Code Protect ................................. 68 Protection Against Spurious Write ............................. 68 Reading ..................................................................... 67 Using .......................................................................... 68 Write Verify ................................................................ 68 Writing ........................................................................ 67 Data Memory ..................................................................... 42 General Purpose Registers ....................................... 42 Map for PIC18F242/442 ............................................ 43 Map for PIC18F252/452 ............................................ 44 Special Function Registers ........................................ 42 DAW ................................................................................ 230 DC and AC Characteristics Graphs and Tables .................................................. 289 DC Characteristics ....................................................261, 265 DCFSNZ .......................................................................... 231 DECF ............................................................................... 230 DECFSZ .......................................................................... 231 Development Support ...................................................... 253 Device Differences ........................................................... 313 Device Overview .................................................................. 7 Features ....................................................................... 7 Direct Addressing ............................................................... 51 Example ..................................................................... 49
E
Electrical Characteristics .................................................. 259 Errata ................................................................................... 5
F
Firmware Instructions ....................................................... 211 FLASH Program Memory ................................................... 55 Associated Registers ................................................. 63 Control Registers ....................................................... 56 Erase Sequence ........................................................ 60 Erasing ....................................................................... 60 Operation During Code Protect ................................. 63 Reading ..................................................................... 59 TABLAT Register ....................................................... 58 Table Pointer ............................................................. 58 Boundaries Based on Operation ........................ 58 Table Pointer Boundaries .......................................... 58 Table Reads and Table Writes .................................. 55 Block Diagrams Reads from FLASH Program Memory ....... 59 Writing to .................................................................... 61 Protection Against Spurious Writes ................... 63 Unexpected Termination .................................... 63 Write Verify ........................................................ 63
G
General Call Address Support ......................................... 148 GOTO .............................................................................. 232
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I
I/O Ports ............................................................................. 87 I2C (MSSP Module) ACK Pulse ................................................................ 139 Read/Write Bit Information (R/W Bit) ....................... 139 I2C (SSP Module) ACK Pulse ................................................................ 138 I2C Master Mode Reception ............................................. 155 I2C Mode Clock Stretching ....................................................... 144 I2C Mode (MSSP Module) ................................................ 134 Registers .................................................................. 134 I2C Module ACK Pulse ........................................................ 138, 139 Acknowledge Sequence Timing ............................... 158 Baud Rate Generator ............................................... 151 Bus Collision Repeated START Condition ............................ 162 START Condition ............................................. 160 Clock Arbitration ....................................................... 152 Effect of a RESET .................................................... 159 General Call Address Support ................................. 148 Master Mode ............................................................ 149 Operation ......................................................... 150 Repeated START Condition Timing ................. 154 Master Mode START Condition ............................... 153 Master Mode Transmission ...................................... 155 Multi-Master Communication, Bus Collision and Arbitration .................................................. 159 Multi-Master Mode ................................................... 159 Operation ................................................................. 138 Read/Write Bit Information (R/W Bit) ............... 138, 139 Serial Clock (RC3/SCK/SCL) ................................... 139 Slave Mode .............................................................. 138 Addressing ....................................................... 138 Reception ......................................................... 139 Transmission .................................................... 139 Slave Mode Timing (10-bit Reception, SEN = 0) .......................................................... 142 Slave Mode Timing (10-bit Reception, SEN = 1) .......................................................... 147 Slave Mode Timing (10-bit Transmission) ................ 143 Slave Mode Timing (7-bit Reception, SEN = 0) .......................................................... 140 Slave Mode Timing (7-bit Reception, SEN = 1) .......................................................... 146 Slave Mode Timing (7-bit Transmission) .................. 141 SLEEP Operation ..................................................... 159 STOP Condition Timing ........................................... 158 ICEPIC In-Circuit Emulator .............................................. 254 ID Locations ............................................................. 195, 210 INCF ................................................................................. 232 INCFSZ ............................................................................ 233 In-Circuit Debugger .......................................................... 210 In-Circuit Serial Programming (ICSP) ...................... 195, 210 Indirect Addressing ............................................................ 51 INDF and FSR Registers ........................................... 50 Indirect Addressing Operation ............................................ 51 Indirect File Operand .......................................................... 42 INFSNZ ............................................................................ 233 Instruction Cycle ................................................................. 39 Instruction Flow/Pipelining ................................................. 40 Instruction Format ............................................................ 213 Instruction Set .................................................................. 211 ADDLW .................................................................... 217 ADDWF .................................................................... 217 ADDWFC ................................................................. 218 ANDLW .................................................................... 218 ANDWF .................................................................... 219 BC ............................................................................ 219 BCF ......................................................................... 220 BN ............................................................................ 220 BNC ......................................................................... 221 BNN ......................................................................... 221 BNOV ...................................................................... 222 BNZ ......................................................................... 222 BOV ......................................................................... 225 BRA ......................................................................... 223 BSF .......................................................................... 223 BTFSC ..................................................................... 224 BTFSS ..................................................................... 224 BTG ......................................................................... 225 BZ ............................................................................ 226 CALL ........................................................................ 226 CLRF ....................................................................... 227 CLRWDT ................................................................. 227 COMF ...................................................................... 228 CPFSEQ .................................................................. 228 CPFSGT .................................................................. 229 CPFSLT ................................................................... 229 DAW ........................................................................ 230 DCFSNZ .................................................................. 231 DECF ....................................................................... 230 DECFSZ .................................................................. 231 GOTO ...................................................................... 232 INCF ........................................................................ 232 INCFSZ .................................................................... 233 INFSNZ .................................................................... 233 IORLW ..................................................................... 234 IORWF ..................................................................... 234 LFSR ....................................................................... 235 MOVF ...................................................................... 235 MOVFF .................................................................... 236 MOVLB .................................................................... 236 MOVLW ................................................................... 237 MOVWF ................................................................... 237 MULLW .................................................................... 238 MULWF .................................................................... 238 NEGF ....................................................................... 239 NOP ......................................................................... 239 POP ......................................................................... 240 PUSH ....................................................................... 240 RCALL ..................................................................... 241 RESET ..................................................................... 241 RETFIE .................................................................... 242 RETLW .................................................................... 242 RETURN .................................................................. 243 RLCF ....................................................................... 243 RLNCF ..................................................................... 244 RRCF ....................................................................... 244 RRNCF .................................................................... 245 SETF ....................................................................... 245 SLEEP ..................................................................... 246 SUBFWB ................................................................. 246 SUBLW .................................................................... 247 SUBWF .................................................................... 247 SUBWFB ................................................................. 248 SWAPF .................................................................... 248
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TBLRD ..................................................................... 249 TBLWT ..................................................................... 250 TSTFSZ .................................................................... 251 XORLW .................................................................... 251 XORWF .................................................................... 252 Summary Table ........................................................ 214 Instructions in Program Memory ........................................ 40 Two-Word Instructions ............................................... 41 INT Interrupt (RB0/INT). See Interrupt Sources INTCON Register RBIF Bit ...................................................................... 90 INTCON Registers ....................................................... 75-77 Inter-Integrated Circuit. See I2C Interrupt Sources .............................................................. 195 A/D Conversion Complete ........................................ 184 Capture Complete (CCP) ......................................... 119 Compare Complete (CCP) ....................................... 120 INT0 ........................................................................... 85 Interrupt-on-Change (RB7:RB4 ) ............................... 90 PORTB, Interrupt-on-Change .................................... 85 RB0/INT Pin, External ................................................ 85 TMR0 ......................................................................... 85 TMR0 Overflow ........................................................ 105 TMR1 Overflow ................................................ 107, 109 TMR2 to PR2 Match ................................................. 112 TMR2 to PR2 Match (PWM) ............................ 111, 122 TMR3 Overflow ................................................ 113, 115 USART Receive/Transmit Complete ........................ 165 Interrupts ............................................................................ 73 Logic ........................................................................... 74 Interrupts, Enable Bits CCP1 Enable (CCP1IE Bit) ...................................... 119 Interrupts, Flag Bits A/D Converter Flag (ADIF Bit) .................................. 183 CCP1 Flag (CCP1IF Bit) .......................................... 119 CCP1IF Flag (CCP1IF Bit) ....................................... 120 Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ........................................................... 90 IORLW ............................................................................. 234 IORWF ............................................................................. 234 IPR Registers ............................................................... 82-83
M
Master SSP (MSSP) Module Overview ........................... 125 Master Synchronous Serial Port (MSSP). See MSSP. Master Synchronous Serial Port. See MSSP Memory Organization Data Memory ............................................................. 42 Program Memory ....................................................... 35 Memory Programming Requirements .............................. 268 Migration from Baseline to Enhanced Devices ................ 314 Migration from High-End to Enhanced Devices ............... 315 Migration from Mid-Range to Enhanced Devices ............ 315 MOVF .............................................................................. 235 MOVFF ............................................................................ 236 MOVLB ............................................................................ 236 MOVLW ........................................................................... 237 MOVWF ........................................................................... 237 MPLAB C17 and MPLAB C18 C Compilers ..................... 253 MPLAB ICD In-Circuit Debugger ..................................... 255 MPLAB ICE High Performance Universal In-Circuit Emulator with MPLAB IDE ....................................... 254 MPLAB Integrated Development Environment Software ............................................. 253 MPLINK Object Linker/MPLIB Object Librarian ............... 254 MSSP ............................................................................... 125 Control Registers (general) ...................................... 125 Enabling SPI I/O ...................................................... 129 Operation ................................................................. 128 Typical Connection .................................................. 129 MSSP Module SPI Master Mode ..................................................... 130 SPI Master./Slave Connection ................................. 129 SPI Slave Mode ....................................................... 131 MULLW ............................................................................ 238 MULWF ............................................................................ 238
N
NEGF ............................................................................... 239 NOP ................................................................................. 239
O
Opcode Field Descriptions ............................................... 212 OPTION_REG Register PSA Bit .................................................................... 105 T0CS Bit .................................................................. 105 T0PS2:T0PS0 Bits ................................................... 105 T0SE Bit ................................................................... 105 Oscillator Configuration ...................................................... 17 EC .............................................................................. 17 ECIO .......................................................................... 17 HS .............................................................................. 17 HS + PLL ................................................................... 17 LP .............................................................................. 17 RC .............................................................................. 17 RCIO .......................................................................... 17 XT .............................................................................. 17 Oscillator Selection .......................................................... 195 Oscillator, Timer1 ..............................................107, 109, 115 Oscillator, Timer3 ............................................................. 113 Oscillator, WDT ................................................................ 203
K
KEELOQ Evaluation and Programming Tools ................... 256
L
LFSR ................................................................................ 235 Lookup Tables Computed GOTO ....................................................... 41 Table Reads, Table Writes ......................................... 41 Low Voltage Detect .......................................................... 189 Converter Characteristics ......................................... 267 Effects of a RESET .................................................. 193 Operation ................................................................. 192 Current Consumption ....................................... 193 During SLEEP .................................................. 193 Reference Voltage Set Point ............................ 193 Typical Application ................................................... 189 LVD. See Low Voltage Detect. ......................................... 189
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P
Packaging ........................................................................ 305 Details ...................................................................... 307 Marking Information ................................................. 305 Parallel Slave Port PORTD .................................................................... 100 Parallel Slave Port (PSP) ........................................... 95, 100 Associated Registers ............................................... 101 RE0/RD/AN5 Pin ................................................ 99, 100 RE1/WR/AN6 Pin ............................................... 99, 100 RE2/CS/AN7 Pin ................................................ 99, 100 Select (PSPMODE Bit) ...................................... 95, 100 PIC18F2X2 Pin Functions MCLR/VPP .................................................................. 10 OSC1/CLKI ................................................................ 10 OSC2/CLKO/RA6 ...................................................... 10 RA0/AN0 .................................................................... 10 RA1/AN1 .................................................................... 10 RA2/AN2/VREF- .......................................................... 10 RA3/AN3/VREF+ ......................................................... 10 RA4/T0CKI ................................................................. 10 RA5/AN4/SS/LVDIN ................................................... 10 RB0/INT0 ................................................................... 11 RB1/INT1 ................................................................... 11 RB2/INT2 ................................................................... 11 RB3/CCP2 ................................................................. 11 RB4 ............................................................................ 11 RB5/PGM ................................................................... 11 RB6/PGC ................................................................... 11 RB7/PGD ................................................................... 11 RC0/T1OSO/T1CKI ................................................... 12 RC1/T1OSI/CCP2 ...................................................... 12 RC2/CCP1 ................................................................. 12 RC3/SCK/SCL ........................................................... 12 RC4/SDI/SDA ............................................................ 12 RC5/SDO ................................................................... 12 RC6/TX/CK ................................................................ 12 RC7/RX/DT ................................................................ 12 VDD ............................................................................. 12 VSS ............................................................................. 12 PIC18F4X2 Pin Functions MCLR/VPP .................................................................. 13 OSC1/CLKI ................................................................ 13 OSC2/CLKO .............................................................. 13 RA0/AN0 .................................................................... 13 RA1/AN1 .................................................................... 13 RA2/AN2/VREF- .......................................................... 13 RA3/AN3/VREF+ ......................................................... 13 RA4/T0CKI ................................................................. 13 RA5/AN4/SS/LVDIN ................................................... 13 RB0/INT ..................................................................... 14 RB1 ............................................................................ 14 RB2 ............................................................................ 14 RB3 ............................................................................ 14 RB4 ............................................................................ 14 RB5/PGM ................................................................... 14 RB6/PGC ................................................................... 14 RB7/PGD ................................................................... 14 RC0/T1OSO/T1CKI ................................................... 15 RC1/T1OSI/CCP2 ...................................................... 15 RC2/CCP1 ................................................................. 15 RC3/SCK/SCL ........................................................... 15 RC4/SDI/SDA ............................................................ 15 RC5/SDO ................................................................... 15 RC6/TX/CK ................................................................ 15 RC7/RX/DT ................................................................ 15 RD0/PSP0 ................................................................. 16 RD1/PSP1 ................................................................. 16 RD2/PSP2 ................................................................. 16 RD3/PSP3 ................................................................. 16 RD4/PSP4 ................................................................. 16 RD5/PSP5 ................................................................. 16 RD6/PSP6 ................................................................. 16 RD7/PSP7 ................................................................. 16 RE0/RD/AN5 .............................................................. 16 RE1/WR/AN6 ............................................................. 16 RE2/CS/AN7 .............................................................. 16 VDD ............................................................................ 16 VSS ............................................................................ 16 PIC18FXX2 Voltage-Frequency Graph (Industrial) ................................................................ 260 PIC18LFXX2 Voltage-Frequency Graph (Industrial) ................................................................ 260 PICDEM 1 Low Cost PICmicro Demonstration Board ............................................... 255 PICDEM 17 Demonstration Board ................................... 256 PICDEM 2 Low Cost PIC16CXX Demonstration Board ............................................... 255 PICDEM 3 Low Cost PIC16CXXX Demonstration Board ............................................... 256 PICSTART Plus Entry Level Development Programmer ............................................................. 255 PIE Registers ................................................................80-81 Pinout I/O Descriptions PIC18F2X2 ................................................................ 10 PIR Registers ................................................................78-79 PLL Lock Time-out ............................................................. 26 Pointer, FSR ...................................................................... 50 POP ................................................................................. 240 POR. See Power-on Reset PORTA Associated Registers ................................................. 89 LATA Register ........................................................... 87 PORTA Register ........................................................ 87 TRISA Register .......................................................... 87 PORTB Associated Registers ................................................. 92 LATB Register ........................................................... 90 PORTB Register ........................................................ 90 RB0/INT Pin, External ................................................ 85 RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) .......... 90 TRISB Register .......................................................... 90 PORTC Associated Registers ................................................. 94 LATC Register ........................................................... 93 PORTC Register ........................................................ 93 RC3/SCK/SCL Pin ................................................... 139 RC7/RX/DT Pin ........................................................ 168 TRISC Register ...................................................93, 165 PORTD Associated Registers ................................................. 96 LATD Register ........................................................... 95 Parallel Slave Port (PSP) Function ............................ 95 PORTD Register ........................................................ 95 TRISD Register .......................................................... 95
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PORTE Analog Port Pins ................................................ 99, 100 Associated Registers ................................................. 99 LATE Register ............................................................ 97 PORTE Register ........................................................ 97 PSP Mode Select (PSPMODE Bit) .................... 95, 100 RE0/RD/AN5 Pin ................................................ 99, 100 RE1/WR/AN6 Pin ............................................... 99, 100 RE2/CS/AN7 Pin ................................................ 99, 100 TRISE Register .......................................................... 97 Postscaler, WDT Assignment (PSA Bit) ............................................... 105 Rate Select (T0PS2:T0PS0 Bits) ............................. 105 Switching Between Timer0 and WDT ...................... 105 Power-down Mode. See SLEEP Power-on Reset (POR) ...................................................... 26 Oscillator Start-up Timer (OST) ................................. 26 Power-up Timer (PWRT) ............................................ 26 Prescaler, Capture ........................................................... 119 Prescaler, Timer0 ............................................................. 105 Assignment (PSA Bit) ............................................... 105 Rate Select (T0PS2:T0PS0 Bits) ............................. 105 Switching Between Timer0 and WDT ...................... 105 Prescaler, Timer2 ............................................................. 122 PRO MATE II Universal Device Programmer ................... 255 Product Identification System ........................................... 327 Program Counter PCL Register .............................................................. 39 PCLATH Register ....................................................... 39 PCLATU Register ....................................................... 39 Program Memory Interrupt Vector .......................................................... 35 Map and Stack for PIC18F442/242 ............................ 36 Map and Stack for PIC18F452/252 ............................ 36 RESET Vector ............................................................ 35 Program Verification and Code Protection ....................... 207 Associated Registers ............................................... 207 Programming, Device Instructions ................................... 211 PSP.See Parallel Slave Port. Pulse Width Modulation. See PWM (CCP Module). PUSH ............................................................................... 240 PWM (CCP Module) ......................................................... 122 Associated Registers ............................................... 123 CCPR1H:CCPR1L Registers ................................... 122 Duty Cycle ................................................................ 122 Example Frequencies/Resolutions ........................... 123 Period ....................................................................... 122 Setup for PWM Operation ........................................ 123 TMR2 to PR2 Match ......................................... 111, 122 Registers ADCON0 (A/D Control 0) ......................................... 181 ADCON1 (A/D Control 1) ......................................... 182 CCP1CON and CCP2CON (Capture/Compare/PWM Control) ................... 117 CONFIG1H (Configuration 1 High) .......................... 196 CONFIG2H (Configuration 2 High) .......................... 197 CONFIG2L (Configuration 2 Low) ........................... 197 CONFIG3H (Configuration 3 High) .......................... 198 CONFIG4L (Configuration 4 Low) ........................... 198 CONFIG5H (Configuration 5 High) .......................... 199 CONFIG5L (Configuration 5 Low) ........................... 199 CONFIG6H (Configuration 6 High) .......................... 200 CONFIG6L (Configuration 6 Low) ........................... 200 CONFIG7H (Configuration 7 High) .......................... 201 CONFIG7L (Configuration 7 Low) ........................... 201 DEVID1 (Device ID Register 1) ............................... 202 DEVID2 (Device ID Register 2) ............................... 202 EECON1 (Data EEPROM Control 1) ....................57, 66 File Summary ........................................................46-48 INTCON (Interrupt Control) ........................................ 75 INTCON2 (Interrupt Control 2) ................................... 76 INTCON3 (Interrupt Control 3) ................................... 77 IPR1 (Peripheral Interrupt Priority 1) ......................... 82 IPR2 (Peripheral Interrupt Priority 2) ......................... 83 LVDCON (LVD Control) ........................................... 191 OSCCON (Oscillator Control) .................................... 21 PIE1 (Peripheral Interrupt Enable 1) .......................... 80 PIE2 (Peripheral Interrupt Enable 2) .......................... 81 PIR1 (Peripheral Interrupt Request 1) ....................... 78 PIR2 (Peripheral Interrupt Request 2) ....................... 79 RCON (Register Control) ........................................... 84 RCON (RESET Control) ............................................ 53 RCSTA (Receive Status and Control) ..................... 167 SSPCON1 (MSSP Control 1) I2C Mode ......................................................... 136 SPI Mode ......................................................... 127 SSPCON2 (MSSP Control 2) I2C Mode ......................................................... 137 SSPSTAT (MSSP Status) I2C Mode ......................................................... 135 SPI Mode ......................................................... 126 STATUS ..................................................................... 52 STKPTR (Stack Pointer) ............................................ 38 T0CON (Timer0 Control) ......................................... 103 T1CON (Timer 1 Control) ........................................ 107 T2CON (Timer 2 Control) ........................................ 111 T3CON (Timer3 Control) ......................................... 113 TRISE ........................................................................ 98 TXSTA (Transmit Status and Control) ..................... 166 WDTCON (Watchdog Timer Control) ...................... 203 RESET ................................................................25, 195, 241 Brown-out Reset (BOR) ........................................... 195 MCLR Reset (During SLEEP) .................................... 25 MCLR Reset (Normal Operation) .............................. 25 Oscillator Start-up Timer (OST) ............................... 195 Power-on Reset (POR) .......................................25, 195 Power-up Timer (PWRT) ......................................... 195 Programmable Brown-out Reset (BOR) .................... 25 RESET Instruction ..................................................... 25 Stack Full Reset ......................................................... 25 Stack Underflow Reset .............................................. 25 Watchdog Timer (WDT) Reset .................................. 25
Q
Q Clock ............................................................................ 122
R
RAM. See Data Memory RC Oscillator ...................................................................... 18 RCALL .............................................................................. 241 RCSTA Register SPEN Bit .................................................................. 165 Register File ....................................................................... 42
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RETFIE ............................................................................ 242 RETLW ............................................................................. 242 RETURN .......................................................................... 243 Revision History ............................................................... 313 RLCF ................................................................................ 243 RLNCF ............................................................................. 244 RRCF ............................................................................... 244 RRNCF ............................................................................. 245
T
TABLAT Register ............................................................... 58 Table Pointer Operations (table) ........................................ 58 TBLPTR Register ............................................................... 58 TBLRD ............................................................................. 249 TBLWT ............................................................................. 250 Time-out Sequence ........................................................... 26 Time-out in Various Situations ................................... 27 Timer0 .............................................................................. 103 16-bit Mode Timer Reads and Writes ...................... 105 Associated Registers ............................................... 105 Clock Source Edge Select (T0SE Bit) ..................... 105 Clock Source Select (T0CS Bit) ............................... 105 Operation ................................................................. 105 Overflow Interrupt .................................................... 105 Prescaler. See Prescaler, Timer0 Timer1 .............................................................................. 107 16-bit Read/Write Mode ........................................... 109 Associated Registers ............................................... 110 Operation ................................................................. 108 Oscillator ...........................................................107, 109 Overflow Interrupt .............................................107, 109 Special Event Trigger (CCP) ............................109, 120 TMR1H Register ...................................................... 107 TMR1L Register ....................................................... 107 Timer2 .............................................................................. 111 Associated Registers ............................................... 112 Operation ................................................................. 111 Postscaler. See Postscaler, Timer2 PR2 Register ....................................................111, 122 Prescaler. See Prescaler, Timer2 SSP Clock Shift ................................................111, 112 TMR2 Register ......................................................... 111 TMR2 to PR2 Match Interrupt ................... 111, 112, 122 Timer3 .............................................................................. 113 Associated Registers ............................................... 115 Operation ................................................................. 114 Oscillator ...........................................................113, 115 Overflow Interrupt .............................................113, 115 Special Event Trigger (CCP) ................................... 115 TMR3H Register ...................................................... 113 TMR3L Register ....................................................... 113 Timing Diagrams Bus Collision Transmit and Acknowledge ..................... 159 A/D Conversion ........................................................ 287 Acknowledge Sequence .......................................... 158 Baud Rate Generator with Clock Arbitration ............ 152 BRG Reset Due to SDA Arbitration During START Condition ............................................. 161 Brown-out Reset (BOR) ........................................... 274 Bus Collision Start Condition (SDA Only) .............................. 160 Bus Collision During a Repeated START Condition (Case 1) .............................. 162 Bus Collision During a Repeated START Condition (Case 2) .............................. 162 Bus Collision During a START Condition (SCL = 0) ......................................................... 161 Bus Collision During a STOP Condition (Case 1) ........................................................... 163 Bus Collision During a STOP Condition (Case 2) ........................................................... 163 Capture/Compare/PWM (CCP1 and CCP2) ............ 276 CLKO and I/O .......................................................... 272 Clock Synchronization ............................................. 145
S
SCI. See USART SCK .................................................................................. 125 SDI ................................................................................... 125 SDO ................................................................................. 125 Serial Clock, SCK ............................................................. 125 Serial Communication Interface. See USART Serial Data In, SDI ........................................................... 125 Serial Data Out, SDO ....................................................... 125 Serial Peripheral Interface. See SPI SETF ................................................................................ 245 Slave Select Synchronization ........................................... 131 Slave Select, SS .............................................................. 125 SLEEP ...............................................................195, 205, 246 Software Simulator (MPLAB SIM) .................................... 254 Special Event Trigger. See Compare Special Features of the CPU ............................................ 195 Configuration Registers ................................... 196-201 Special Function Registers ................................................ 42 Map ............................................................................ 45 SPI Master Mode ............................................................ 130 Serial Clock .............................................................. 125 Serial Data In ........................................................... 125 Serial Data Out ........................................................ 125 Slave Select ............................................................. 125 SPI Clock ................................................................. 130 SPI Mode ................................................................. 125 SPI Master/Slave Connection .......................................... 129 SPI Module Associated Registers ............................................... 133 Bus Mode Compatibility ........................................... 133 Effects of a RESET .................................................. 133 Master/Slave Connection ......................................... 129 Slave Mode .............................................................. 131 Slave Select Synchronization .................................. 131 Slave Synch Timing ................................................. 131 SLEEP Operation ..................................................... 133 SS .................................................................................... 125 SSP I2C Mode. See I2C SPI Mode ................................................................. 125 SPI Mode. See SPI SSPBUF Register .................................................... 130 SSPSR Register ...................................................... 130 TMR2 Output for Clock Shift ............................ 111, 112 SSPOV Status Flag .......................................................... 155 SSPSTAT Register R/W Bit ............................................................. 138, 139 Status Bits Significance and the Initialization Condition for RCON Register ............................................. 27 SUBFWB .......................................................................... 246 SUBLW ............................................................................ 247 SUBWF ............................................................................ 247 SUBWFB .......................................................................... 248 SWAPF ............................................................................ 248
2002 Microchip Technology Inc.
DS39564B-page 323
PIC18FXX2
Example SPI Master Mode (CKE = 0) ..................... 278 Example SPI Master Mode (CKE = 1) ..................... 279 Example SPI Slave Mode (CKE = 0) ....................... 280 Example SPI Slave Mode (CKE = 1) ....................... 281 External Clock (All Modes except PLL) .................... 271 First START Bit Timing ............................................ 153 I2C Bus Data ............................................................ 282 I2C Bus START/STOP Bits ...................................... 282 I2C Master Mode (Reception, 7-bit Address) ........... 157 I2C Master Mode (Transmission, 7 or 10-bit Address) ......................................... 156 I2C Slave Mode Timing (10-bit Reception, SEN = 0) .......................................................... 142 I2C Slave Mode Timing (10-bit Transmission) ......... 143 I2C Slave Mode Timing (7-bit Reception, SEN = 0) .......................................................... 140 I2C Slave Mode Timing (7-bit Reception, SEN = 1) .................................................. 146, 147 I2C Slave Mode Timing (7-bit Transmission) ........... 141 Low Voltage Detect .................................................. 192 Master SSP I2C Bus Data ........................................ 284 Master SSP I2C Bus START/STOP Bits .................. 284 Parallel Slave Port (PIC18F4X2) .............................. 277 Parallel Slave Port (Read) ........................................ 101 Parallel Slave Port (Write) ........................................ 100 PWM Output ............................................................. 122 Repeat START Condition ......................................... 154 RESET, Watchdog Timer (WDT), Oscillator Start-up Timer (OST) and Power-up Timer (PWRT) ................................. 273 Slave Synchronization .............................................. 131 Slaver Mode General Call Address Sequence (7 or 10-bit Address Mode) .............................. 148 Slow Rise Time (MCLR Tied to VDD) ......................... 33 SPI Mode (Master Mode) ......................................... 130 SPI Mode (Slave Mode with CKE = 0) ..................... 132 SPI Mode (Slave Mode with CKE = 1) ..................... 132 Stop Condition Receive or Transmit Mode .............. 158 Time-out Sequence on POR w/PLL Enabled (MCLR Tied to VDD) ........................................... 33 Time-out Sequence on Power-up (MCLR Not Tied to VDD) Case 1 ................................................................ 32 Case 2 ................................................................ 32 Time-out Sequence on Power-up (MCLR Tied to VDD) ........................................... 32 Timer0 and Timer1 External Clock ........................... 275 Timing for Transition Between Timer1 and OSC1 (HS with PLL) .......................................... 23 Transition Between Timer1 and OSC1 (HS, XT, LP) ....................................................... 22 Transition Between Timer1 and OSC1 (RC, EC) ............................................................ 23 Transition from OSC1 to Timer1 Oscillator ................ 22 USART Asynchronous Master Transmission ........... 173 USART Asynchronous Master Transmission (Back to Back) .................................................. 173 USART Asynchronous Reception ............................ 175 USART Synchronous Receive (Master/Slave) ......... 286 USART Synchronous Reception (Master Mode, SREN) ...................................... 178 USART Synchronous Transmission ......................... 177 USART Synchronous Transmission (Master/Slave) .................................................. 286 USART Synchronous Transmission (Through TXEN) .............................................. 177 Wake-up from SLEEP via Interrupt .......................... 206 Timing Diagrams Requirements Master SSP I2C Bus START/STOP Bits .................. 284 Timing Requirements A/D Conversion ........................................................ 288 Capture/Compare/PWM (CCP1 and CCP2) ............ 276 CLKO and I/O .......................................................... 273 Example SPI Mode (Master Mode, CKE = 0) .......... 278 Example SPI Mode (Master Mode, CKE = 1) .......... 279 Example SPI Mode (Slave Mode, CKE = 0) ............ 280 Example SPI Slave Mode (CKE = 1) ....................... 281 External Clock .......................................................... 271 I2C Bus Data (Slave Mode) ..................................... 283 Master SSP I2C Bus Data ........................................ 285 Parallel Slave Port (PIC18F4X2) ............................. 277 RESET, Watchdog Timer, Oscillator Start-up Timer, Power-up Timer and Brown-out Reset Requirements ....................... 274 Timer0 and Timer1 External Clock .......................... 275 USART Synchronous Receive ................................. 286 USART Synchronous Transmission ........................ 286 Timing Specifications PLL Clock ................................................................ 272 TRISE Register PSPMODE Bit .....................................................95, 100 TSTFSZ ........................................................................... 251 Two-Word Instructions Example Cases .......................................................... 41 TXSTA Register BRGH Bit ................................................................. 168
U
Universal Synchronous Asynchronous Receiver Transmitter. See USART USART ............................................................................. 165 Asynchronous Mode ................................................ 172 Associated Registers, Receive ........................ 175 Associated Registers, Transmit ....................... 173 Receiver .......................................................... 174 Transmitter ....................................................... 172 Baud Rate Generator (BRG) ................................... 168 Associated Registers ....................................... 168 Baud Rate Error, Calculating ........................... 168 Baud Rate Formula .......................................... 168 Baud Rates for Asynchronous Mode (BRGH = 0) .............................................. 170 Baud Rates for Asynchronous Mode (BRGH = 1) .............................................. 171 Baud Rates for Synchronous Mode ................. 169 High Baud Rate Select (BRGH Bit) ................. 168 Sampling .......................................................... 168 Serial Port Enable (SPEN Bit) ................................. 165 Synchronous Master Mode ...................................... 176 Associated Registers, Reception ..................... 178 Associated Registers, Transmit ....................... 176 Reception ........................................................ 178 Transmission ................................................... 176 Synchronous Slave Mode ........................................ 179 Associated Registers, Receive ........................ 180 Associated Registers, Transmit ....................... 179 Reception ........................................................ 180 Transmission ................................................... 179
DS39564B-page 324
2002 Microchip Technology Inc.
PIC18FXX2
W
Wake-up from SLEEP .............................................. 195, 205 Using Interrupts ........................................................ 205 Watchdog Timer (WDT) ........................................... 195, 203 Associated Registers ............................................... 204 Control Register ....................................................... 203 Postscaler ........................................................ 203, 204 Programming Considerations .................................. 203 RC Oscillator ............................................................ 203 Time-out Period ....................................................... 203 WCOL .............................................................................. 153 WCOL Status Flag ............................................153, 155, 158 WWW, On-Line Support ....................................................... 5
X
XORLW ............................................................................ 251 XORWF ........................................................................... 252
2002 Microchip Technology Inc.
DS39564B-page 325
PIC18FXX2
NOTES:
DS39564B-page 326
2002 Microchip Technology Inc.
PIC18FXX2
ON-LINE SUPPORT
Microchip provides on-line support on the Microchip World Wide Web site. The web site is used by Microchip as a means to make files and information easily available to customers. To view the site, the user must have access to the Internet and a web browser, such as Netscape(R) or Microsoft(R) Internet Explorer. Files are also available for FTP download from our FTP site.
SYSTEMS INFORMATION AND UPGRADE HOT LINE
The Systems Information and Upgrade Line provides system users a listing of the latest versions of all of Microchip's development systems software products. Plus, this line provides information on how customers can receive the most current upgrade kits.The Hot Line Numbers are: 1-800-755-2345 for U.S. and most of Canada, and 1-480-792-7302 for the rest of the world. 092002
Connecting to the Microchip Internet Web Site
The Microchip web site is available at the following URL: www.microchip.com The file transfer site is available by using an FTP service to connect to: ftp://ftp.microchip.com The web site and file transfer site provide a variety of services. Users may download files for the latest Development Tools, Data Sheets, Application Notes, User's Guides, Articles and Sample Programs. A variety of Microchip specific business information is also available, including listings of Microchip sales offices, distributors and factory representatives. Other data available for consideration is: * Latest Microchip Press Releases * Technical Support Section with Frequently Asked Questions * Design Tips * Device Errata * Job Postings * Microchip Consultant Program Member Listing * Links to other useful web sites related to Microchip Products * Conferences for products, Development Systems, technical information and more * Listing of seminars and events
2002 Microchip Technology Inc.
DS39564B-page 327
PIC18FXX2
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: RE: Technical Publications Manager Reader Response Total Pages Sent ________
From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ Application (optional): Would you like a reply? Device: PIC18FXX2 Questions: 1. What are the best features of this document? Y N Literature Number: DS39564B FAX: (______) _________ - _________
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this document easy to follow? If not, why?
4. What additions to the document do you think would enhance the structure and subject?
5. What deletions from the document could be made without affecting the overall usefulness?
6. Is there any incorrect or misleading information (what and where)?
7. How would you improve this document?
DS39564B-page 328
2002 Microchip Technology Inc.
PIC18FXX2
PIC18FXX2 PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO. Device
-
X Temperature Range
/XX Package
XXX Pattern
Examples: a) PIC18LF452 - I/P 301 = Industrial temp., PDIP package, Extended VDD limits, QTP pattern #301. PIC18LF242 - I/SO = Industrial temp., SOIC package, Extended VDD limits. PIC18F442 - E/P = Extended temp., PDIP package, normal VDD limits.
Device
PIC18FXX2(1), PIC18FXX2T(2); VDD range 4.2V to 5.5V PIC18LFXX2(1), PIC18LFXX2T(2); VDD range 2.5V to 5.5V I E PT SO SP P L = = = = = = = -40C to +85C (Industrial) -40C to +125C (Extended) TQFP (Thin Quad Flatpack) SOIC Skinny Plastic DIP PDIP PLCC
b) c)
Temperature Range Package
Note 1: F LF 2: T
= Standard Voltage range = Wide Voltage Range = in tape and reel - SOIC, PLCC, and TQFP packages only.
Pattern
QTP, SQTP, Code or Special Requirements (blank otherwise)
Sales and Support
Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following: 1. 2. 3. Your local Microchip sales office The Microchip Corporate Literature Center U.S. FAX: (480) 792-7277 The Microchip Worldwide Site (www.microchip.com)
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using. New Customer Notification System Register on our web site (www.microchip.com/cn) to receive the most current information on our products.
2002 Microchip Technology Inc.
DS39564B-page 329
M
WORLDWIDE SALES AND SERVICE
AMERICAS
Corporate Office
2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: 480-792-7627 Web Address: http://www.microchip.com
ASIA/PACIFIC
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Microchip Technology Australia Pty Ltd Suite 22, 41 Rawson Street Epping 2121, NSW Australia Tel: 61-2-9868-6733 Fax: 61-2-9868-6755
Japan
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Rocky Mountain
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China - Beijing
Microchip Technology Consulting (Shanghai) Co., Ltd., Beijing Liaison Office Unit 915 Bei Hai Wan Tai Bldg. No. 6 Chaoyangmen Beidajie Beijing, 100027, No. China Tel: 86-10-85282100 Fax: 86-10-85282104
Korea
Microchip Technology Korea 168-1, Youngbo Bldg. 3 Floor Samsung-Dong, Kangnam-Ku Seoul, Korea 135-882 Tel: 82-2-554-7200 Fax: 82-2-558-5934
Atlanta
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Singapore
Microchip Technology Singapore Pte Ltd. 200 Middle Road #07-02 Prime Centre Singapore, 188980 Tel: 65-6334-8870 Fax: 65-6334-8850
Boston
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China - Chengdu
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Taiwan
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Dallas
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China - Fuzhou
Microchip Technology Consulting (Shanghai) Co., Ltd., Fuzhou Liaison Office Unit 28F, World Trade Plaza No. 71 Wusi Road Fuzhou 350001, China Tel: 86-591-7503506 Fax: 86-591-7503521
Detroit
Tri-Atria Office Building 32255 Northwestern Highway, Suite 190 Farmington Hills, MI 48334 Tel: 248-538-2250 Fax: 248-538-2260
EUROPE
Austria
Microchip Technology Austria GmbH Durisolstrasse 2 A-4600 Wels Austria Tel: 43-7242-2244-399 Fax: 43-7242-2244-393
China - Shanghai
Microchip Technology Consulting (Shanghai) Co., Ltd. Room 701, Bldg. B Far East International Plaza No. 317 Xian Xia Road Shanghai, 200051 Tel: 86-21-6275-5700 Fax: 86-21-6275-5060
Kokomo
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Denmark
Microchip Technology Nordic ApS Regus Business Centre Lautrup hoj 1-3 Ballerup DK-2750 Denmark Tel: 45 4420 9895 Fax: 45 4420 9910
Los Angeles
18201 Von Karman, Suite 1090 Irvine, CA 92612 Tel: 949-263-1888 Fax: 949-263-1338
China - Shenzhen
Microchip Technology Consulting (Shanghai) Co., Ltd., Shenzhen Liaison Office Rm. 1315, 13/F, Shenzhen Kerry Centre, Renminnan Lu Shenzhen 518001, China Tel: 86-755-82350361 Fax: 86-755-82366086
New York
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France
Microchip Technology SARL Parc d'Activite du Moulin de Massy 43 Rue du Saule Trapu Batiment A - ler Etage 91300 Massy, France Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
San Jose
Microchip Technology Inc. 2107 North First Street, Suite 590 San Jose, CA 95131 Tel: 408-436-7950 Fax: 408-436-7955
China - Hong Kong SAR
Microchip Technology Hongkong Ltd. Unit 901-6, Tower 2, Metroplaza 223 Hing Fong Road Kwai Fong, N.T., Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431
Germany
Microchip Technology GmbH Steinheilstrasse 10 D-85737 Ismaning, Germany Tel: 49-89-627-144 0 Fax: 49-89-627-144-44
Toronto
6285 Northam Drive, Suite 108 Mississauga, Ontario L4V 1X5, Canada Tel: 905-673-0699 Fax: 905-673-6509
India
Microchip Technology Inc. India Liaison Office Divyasree Chambers 1 Floor, Wing A (A3/A4) No. 11, O'Shaugnessey Road Bangalore, 560 025, India Tel: 91-80-2290061 Fax: 91-80-2290062
Italy
Microchip Technology SRL Centro Direzionale Colleoni Palazzo Taurus 1 V. Le Colleoni 1 20041 Agrate Brianza Milan, Italy Tel: 39-039-65791-1 Fax: 39-039-6899883
United Kingdom
Microchip Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44 118 921 5869 Fax: 44-118 921-5820
08/01/02
DS39564B-page 330
2002 Microchip Technology Inc.


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